Computers viruses, worms, ransomware, etc. are kinds of malicious software that no user should take lightly. On several occasions, we have touched upon security steps that each user should take in order to protect its identity and data. Sadly sometimes even when all precautions are taken some malware can still slip through and wreak havoc. Today we are looking at some of the worst or the best, depending on your view that has indeed wreaked plenty of havoc.

10 worst computer viruses in history

In the list of the 10 most famous computer viruses below, we show the costs, dates, reach, and other key facts. First a note about terms: we use the words “virus” and “worm” interchangeably because most readers search for them that way. But there’s a subtle difference that we explain after the list.

1. Mydoom – $38 billion

The worst computer virus outbreak in history, Mydoom caused estimated damage of $38 billion in 2004, but its inflation-adjusted cost is actually $52.2 billion. Also known as Novarg, this malware is technically a “worm,” spread by mass emailing. At one point, the Mydoom virus was responsible for 25% of all emails sent. Mydoom scraped addresses from infected machines, then sent copies of itself to those addresses. It also roped those infected machines into a web of computers called a botnet that performed distributed denial of service (DDoS) attacks. These attacks were intended to shut down a target website or server. Mydoom is still around today, generating 1% of all phishing emails. That’s no small feat considering the 3.4 billion phishing emails sent each day. By that figure, Mydoom has taken on a life of its own, infecting enough poorly-protected machines to send 1.2 billion copies of itself per year, 16 years after its creation. Though a $250,000 reward was offered, the developer of this dangerous computer worm was never caught. Wondering what makes the world’s most secure computers so safe? See the Tech@Work guide: Upgrade to the World's Most Secure and Manageable PC

2. Sobig – $30 billion

The 2003 Sobig computer virus is actually another worm. It is second only to the Mydoom virus in its scope. The $30 billion figure is a worldwide total, including Canada, the U.K., the U.S., mainland Europe, and Asia. Several versions of the worm were released in quick succession, named Sobig.A through Sobig.F, with Sobig.F being the most damaging. This cybercriminal program masqueraded as legitimate computer software attached to emails. It disrupted ticketing at Air Canada and interfered with countless other businesses. Despite its widespread damage, the creator of the successful bug was never caught.

3. Klez – $19.8 billion

Klez is a close third on the list of the worst computer viruses ever created. With nearly $20 billion in estimated damages, it infected about 7.2% of all computers in 2001, or 7 million PCs. The Klez worm sent fake emails, spoofed recognized senders and, among other things, attempted to deactivate other viruses. As with other viruses and worms, Klez was released in several variants. It infected files, copied itself, and spread throughout each victim’s network. It hung around for years, with each version more destructive than the last. Windows has come a long way since most of the computer viruses on this list hit the web. Thankfully, built-in protection with Microsoft Defender is always on the watch.

4. ILOVEYOU – $15 billion

The year 2000’s ILOVEYOU virus worked by sending a bogus “love letter” that looked like a harmless text file. Like Mydoom, this attacker sent copies of itself to every email address in the infected machine’s contact list. Shortly after its May 4 release, it had spread to more than 10 million PCs. The virus was created by a college student in the Philippines named Onel de Guzman. Lacking funds, he wrote the virus to steal passwords so he could log into online services he wanted to use for free. He reportedly had no idea how far his creation would spread. This virus is also known as Loveletter. Need to up your remote work security game before there’s another entry on the list of most deadly computer viruses? See our guide: How to Work Remotely and Securely

5. WannaCry – $4 billion

The 2017 WannaCry computer virus is ransomware, a virus that takes over your computer (or cloud files) and holds them hostage. The WannaCry ransomware ripped through computers in 150 countries, causing massive productivity losses as businesses, hospitals, and government organizations that didn’t pay were forced to rebuild systems from scratch. The malware raged like wildfire through 200,000 computers worldwide. It stopped when a 22-year-old security researcher in the U.K. found a way to turn it off. Computers with out-of-date operating systems were hit especially hard. That’s why security experts always recommend updating your systems frequently.

Ransomware strikes again

In September 2020, one of the potentially largest computer virus attacks in medical history hit Universal Health Services. The U.S. hospital chain, which has more than 400 locations, was reportedly struck by damaging ransomware. The attack forced the cancellation of surgeries and made healthcare workers switch to paper records.

6. Zeus – $3 billion

The Zeus computer virus is an online theft tool that hit the web in 2007. A whitepaper by Unisys three years later estimated that it was behind 44% of all banking malware attacks. By then, it had breached 88% of all Fortune 500 companies, 2,500 organizations total, and 76,000 computers in 196 countries. The Zeus botnet was a group of programs that worked together to take over machines for a remote “bot master.” It originated in Eastern Europe and was used to transfer money to secret bank accounts. More than 100 members of the crime ring behind the virus, mostly in the U.S., were arrested in 2010. It’s not as prominent today, but some of the virus’ source code lives on in newer botnet viruses and worms. Zeus caused documented damage of $100 million. But the real cost in terms of lost productivity, removal, and undocumented theft is undoubtedly much higher. A $3 billion estimate, adjusted for inflation, puts this virus at a cost of $3.7 billion in today’s dollars.

7. Code Red – $2.4 billion

First observed in 2001, the Code Red computer virus was yet another worm that penetrated 975,000 hosts. It displayed the words “Hacked by Chinese!” across infected web pages, and it ran entirely in each machine’s memory. In most cases it left no trace in hard drives or other storage. Financial costs are pegged at $2.4 billion. The virus attacked websites of infected computers and delivered a distributed denial of service (DDoS) attack on the U.S. White House’s website, www.whitehouse.gov. In fact, the White House had to change its IP address to defend against Cod Red. Can your printer get a virus? See our cool infographic: The State of Printer Security

8. Slammer – $1.2 billion

The SQL Slammer worm cost an estimated $750 million across 200,000 computer users in 2003. This computer virus randomly selected IP addresses, exploiting vulnerabilities and sending itself on to other machines. It used these victim machines to launch a DDoS attack on several internet hosts, significantly slowing internet traffic. The Slammer worm hit banks in the U.S. and Canada especially hard, taking ATMs offline in many locations. Customers of Toronto’s Imperial Bank of Commerce found themselves unable to access funds. The attack reared its ugly head again in 2016, launching from IP addresses in Ukraine, China, and Mexico.

9. CryptoLocker – $665 million

Thankfully, ransomware attacks like the 2013 CryptoLocker virus have dipped since their 2017 peak. This malware attacked upwards of 250,000 machines by encrypting their files. It displayed a red ransom note informing users that “your important files encryption produced on this computer.” A payment window accompanied the note. The virus’ creators used a worm called the Gameover Zeus botnet to make and send copies of the CryptoLocker virus. According to a report by security firm Sophos, the average ransomware attack costs a business $133,000. If we estimate that CryptoLocker hit 5,000 companies, that would put its total cost at $665 million. Where will cybersecurity go next? See our guide: The Future of Cybersecurity

10. Sasser – $500 million

The Sasser worm was written by a 17-year-old German computer science student named Sven Jaschan. He was arrested at the age of 18 in 2004 after a $250,000 bounty was posted for the computer virus’ creator. A friend of Jaschan’s tipped authorities that the youth had penned not only the Sasser worm but also the damaging Netsky.AC attack. Jaschan was given a suspended sentence after it was found he was a minor when he wrote the malware. The Sasser worm crashed millions of PCs, and though some reports put damages at $18 billion, the relatively low infection rate suggests a more likely cost of $500 million. Other notable viruses The top 10 worst computer viruses above are just the ugly tip of a gargantuan digital iceberg. With a million new malware programs popping up every 3 years, we may miss the forest for a few outstanding trees. Here are just a few more viruses that have wreaked havoc over the years: Mimail: This worm tried to harvest data from infected machines to launch a string of DDoS attacks, but was relatively easy to remove. Yaha: Yet another worm with several variants, thought to be the result of a cyber-war between Pakistan and India. Swen: Written in C++, the Swen computer worm disguised itself to look like a 2003 OS update. Its financial cost has been pegged at $10.4 billion, but not reliably. Storm Worm: This worm showed up in 2007 and attacked millions of computers with an email about approaching bad weather. Tanatos/Bugbear: A 2002 keylogger virus that targeted financial institutions and spread to 150 countries. Sircam: A computer worm from 2001 that used counterfeit emails with the subject line, “I send you this file in order to have your advice.” Explorezip: This worm used fake emails to spread to every machine on thousands of local networks. Melissa: The most dangerous computer virus in 1999, Melissa sent copies of itself that looked like NSFW pics. The U.S. FBI estimated cleanup and repair costs at $80 million. Flashback: A Mac-only virus, Flashback infected over 600,000 Macs in 2012 and even infected Apple’s home base in Cupertino, Calif. In 2020, there’s now more malware on Macs than on PCs. Conficker: This 2009 virus still infects many legacy systems and could do significant damage if it ever activates. Stuxnet: This worm is reported to have destroyed Iranian nuclear centrifuges by sending damaging instructions.

If you have a BlueTooth device on your computer, you know that each time you need to receive or transfer the file you need to find the icon in the system tray, right-click on it and choose the desired option. But there is a simpler solution, create a Bluetooth icon on the desktop so it is always easy to access. Open File Explorer by pressing ⊞ WINDOWS + E Go to C:\Windows\System32 Find fsquirt.exe Right-click on it and choose copy Go to the desktop and right-click, choose paste Rename the file to Bluetooth And, you are done!

If VirtualBox suddenly displays a black screen without any text or mouse cursor when you are trying to boot a guest operating system, then read on as this post will guide you in fixing such an issue. This black screen occurs when Windows 10 failed to provide a specific setting that VirtualBox requires. Consequently, you will not be able to install or use any guest operating system in VirtualBox even if your PC has virtualization support, the best thing you can do now is to fix this black screen issue. There are two ways you can fix this black screen in VirtualBox, you can either try to disable Hyber-V or disable 3D Acceleration. For more details, refer to each one of the given options below.

Option 1 – Try to disable Hyper-V

Hyper-V is a built-in virtualization tool available in Windows that helps users in creating a virtual machine as well as install a guest operating system without using any third-party tool like VMware, VirtualBox, and many more. However, the problem with this virtualization tool is that some systems cannot run it and VirtualBox simultaneously which is most likely why the screen abruptly turns into black. Thus, you have to disable Hyper-V to resolve the problem. How? Refer to these steps:

• In the Start Search, type “Turn Windows features on or off” and then click on it from the results.
• Once you’ve opened the Windows Features window, remove the checkmark from the Hyper-V box.
• Click the OK button and then restart your computer.
• Now try to use VirtualBox again and see if the problem is fixed.

Option 2 – Try to disable 3D Acceleration

The guest operating system will use the host computer’s GPU to render 3D graphics if you enable the 3D Acceleration for the virtual machine. To simply put it, it will enhance the graphics of the virtual machine and will let you use 3D graphics. Although it may seem nice, it can actually cause the black screen to appear as well so you might have to disable it to isolate the problem. In fact, a lot of operating systems have failed to use the 3D Acceleration for the guest operating system because of this black screen issue. To disable it, follow these steps:

• Open VirtualBox on your computer and select the virtual machine.
• Next, click on the Settings button and go to the Display section.
• After that, look for a checkbox named “Enable 3D Acceleration” located on your right-hand side and then uncheck it.
• Save the changes you’ve made and reboot your PC and see if you can now run the virtual machine without any problem.

Recently, a number of Windows 10 users reported that they were not able to use Cortana properly because it wasn’t able to connect to the internet. According to these users, Cortana won’t connect to the internet even when their internet connection is stable. According to security experts, this issue is confirmed to occur only with Microsoft accounts. This problem might have something to do with a proxy server that interferes with Cortana. There were reports that this issue was caused by a proxy that was filtering the network connection which also happens to interfere with Cortana’s ability to adapt search results and queries based on the user’s location. It could also be caused by some glitch in the home network or your Microsoft account information is inconsistent or your Microsoft account has to be verified. Here are some suggestions that could help fix the connection issue in Cortana, just start with the first one and work your way down until you encounter an option that fixes the problem.

Option 1 – Restart or reset your modem or router

The first thing you can try is restarting or resetting your modem or router. All you have to do is unplug the power cable of the modem and then plug it back in after a few seconds. You could also use the reset button of the modem at the back if it is one. But before you press the reset button, keep in mind that it will erase all the connection credentials and it will be set back to its default settings. After rebooting the network, you can restart your computer to force your modem or router to reassign an IP address to your computer.

Option 2 – Restart Cortana

Restarting Cortana can help you resolve the issue.

• To restart Cortana, open the Task Manager, right-click on Cortana and select the “End process” option.
• Then go to the File tab and select “Run new task”.
• After that, type in “cortana.exe” and press Enter to restart the process.

Option 3 – Try to remove Proxy

Removing the Proxy might also help you in fixing the connection issue in Cortana. Here’s how you can do it:

• Tap the Win + R keys to open the Run dialog box.
• Then type “inetcpl.cpl” in the field and hit Enter to pull up the Internet Properties.
• After that, go to the Connections tab and select the LAN settings.
• From there. Uncheck the “Use a Proxy Server” option for your LAN and then make sure that the “Automatically detect settings” option is checked.
• Now click the OK and the Apply buttons.
• Restart your PC.

Note: If you are using a third-party proxy service, you have to disable it.

Option 4 – Open another app that uses a Microsoft account

This might seem like an odd fix, however, a couple of users tried doing this and it worked for them as it allowed Cortana to connect to the internet again. In this option, you just have to launch another app that uses your Microsoft account information in the same way as Cortana, for instance, the Store app. Once you open the app, a prompt should appear along with a dialog box that allows you to update your Microsoft account with the information required. After that, restart your computer and check if Cortana is now able to connect to the internet or not.

Option 5 – Verify your Microsoft account

In some cases, Cortana might not be able to connect to the internet because your Microsoft account is no longer verified. This usually happens when you use a two-step authentication system with your Microsoft account. To verify it, just open Settings and click on Accounts. After that, check if you have a Verify hyperlink under your Microsoft account or not then click on Verify. Afterward, follow the next on-screen prompts to verify your Microsoft account. Once your account is verified, restart your computer.

Option 6 – Reset Cortana settings

• Open Cortana and go to the Settings section where you’ll see the “Turning off Cortana clears what Cortana knows on this device, but won’t delete anything from the Notebook. After Cortana is off, you can decide what you’d like to do with anything still stored in the cloud” option. Turn this option off.
• Restart your PC.
• After your computer boots, launch Cortana again and check.

If you are trying to copy large files that are over 4GB to a USB flash drive or SD card, but you suddenly get an error message saying, “File Too Large, The file is too large for the destination file system”, read on as this post will help you fix this problem. A user recently reported that while trying to copy a 4.8GB zipped file from a Windows 10 PC to a new 8GB USB drive but only got the File Too Large error message instead. If you share the same problem with this user and you know that there is more than enough available space for the file in your USB drive or SD card, continue reading until you get to the instructions provided in this post so that you will be able to copy the file successfully. It is most likely that the USB drive has been FAT32 formatted which is why you’re unable to copy the file and got an error. The FAT32 file system has a built-in limitation on the size of the individual file that it may contain. For instance, it’s 4GB so even though collectively, it may have files or even 1TB individually it shouldn’t be more than 4GB. Thus, you need to change the file system from FAT32 to NTFS. To do that, carefully follow the instructions provided below.

• Step 1: Connect the USB drive and open the Windows File Explorer.
• Step 2: Afterwards, right-click on the USB drive letter and select Format from the context menu.
• Step 3: Next, select NTFS instead of FAT32 the instant a dialog box appears from the drop-down menu for the file system.
• Step 4: Now click on the Quick Format option and then click the Start button to reformat the USB drive.

Note: There is also another way you can change the file system. In this alternative way, you need to open an elevated Command Prompt and type the convert X: /fs:ntfs /nosecurity command, and hit Enter to execute it. Remember that in this command, “X” is the letter of your USB drive so whatever the letter of your drive is, you need to make sure to put it instead of “X”. Once the process is completed, try copying the file again.

These days, Google Chrome is definitely one of the most used browsers in the browser. Google has almost created a nearly perfect product that rarely experiences problems. However, a lot of users have reported an issue where some files they’re downloading or their downloads in their Google Chrome browsers are stuck at 100%. So if you are one of these users, read on as this post will guide you on what you can do to resolve the problem. This kind of problem could be caused by several factors. It is possible that the file download process could be blocked by a third-party antivirus or it could be that the content-length header could be missing from the server. Aside from that, a Google Chrome extension could also be the culprit or it could be that the current installation of the browser could be corrupted. This kind of problem can get really annoying as the download process has already utilized system resources as well as take up your time. Thus, you need to fix the problem using several suggestions. You can try to clear the browser cache, disable the Chrome virus scan, whitelist the file on the third-party antivirus program, put your browser in Incognito mode and download the file again. On the other hand, you could also try to reset or reinstall the browser. For more details, follow the options provided below.

Option 1 – Try to clear browser cache and try downloading again

There are times when some data in the browser is conflicting with the loading of the website and triggers some problems like download getting stuck at 100%. And so you can try to clear your browser’s data. This might be a very basic solution but oftentimes it works in fixing this kind of error in Google Chrome. Follow the steps below to clear the data in your browser.

• Open your Google Chrome browser.
• After that, tap the Ctrl + H keys. Doing so will open a new panel that allows you to delete the browsing history and other data in your browser.
• Now select every checkbox that you see and click on the Clear data button.
• Then restart your Chrome browser and check if you can now complete the download again.

Option 2 – Try disabling Chrome virus scan

The next thing you can do to resolve the problem is to disable the Chrome virus scan. It is possible that the virus scan is the one that’s preventing the download to be completed, thus, try to disable it and see if it works.

Option 3 – Whitelist the file you’re downloading in your antivirus program

The download getting stuck might also be caused by your antivirus program which could be interfering it from running. To fix this, you have to whitelist dism.exe. How? Refer to these steps:

• Open the Windows Defender Security Center from the system tray area.
• Next, click the “Virus & threat protection” option and then open the “Virus and threat protection settings”.
• After that, scroll down until you find the “Exclusions” and click on the “Add or remove exclusions” option.
• Then click the plus button and select the type of exclusion you want to add and from the drop-down list, select Folder.
• Next, navigate to this path and select the WinSxS folder: C:/Windows/WinSxS
• When a User Account Control or UAC prompt, just click on Yes to proceed.

Option 4 – Try downloading the file in Incognito mode

There are certain browser extensions, especially those security programs, that prevent any suspicious files from being downloaded. So the easy way to fix the problem is to launch the Chrome browser in Incognito mode and then try to download the file again. Additionally, you might want to consider disabling the problematic extension.

Option 5 – Reset Chrome

Resetting Chrome can also help you fix the problem. This means that you will be restoring its default settings, disabling all the extensions, add-ons, and themes. Aside from that, the content settings will be reset as well and the cookies, cache, and site data will also be deleted. To reset Chrome, here’s what you have to do:

• Open Google Chrome, then tap the Alt + F keys.
• After that, click on Settings.
• Next, scroll down until you see the Advanced option, once you see it, click on it.
• After clicking the Advanced option, go to the “Restore and clean up option and click on the “Restore settings to their original defaults” option to reset Google Chrome.
• Now restart Google Chrome.

Option 6 – Try to clean reinstall Chrome

There are instances when programs leave files behind after you’ve uninstalled them and the same thing can happen to Chrome so before you reinstall Chrome, you have to make sure that you have deleted the User Data folder. To do so, refer to the following steps:

• Hit the Win + R keys to open the Run dialog box.
• Next, type “%LOCALAPPDATA%GoogleChromeUser Data” in the field and hit Enter to open the User Data folder.
• From there, rename the default folder and name it something else, e.g. “Default.old”.
• After that, install Google Chrome again and check if the issue is now fixed.

If you find it hard to update Google Chrome to its latest version and each time you try to do so it keeps on failing, worry not for this post will guide you in fixing a list of Google Chrome Update errors. Even though there are a lot of error codes around Chrome, these are only caused by issues with the update. Here are some of the errors you can encounter when updating Google Chrome:

• Update failed: You can encounter this error when the Updates are disabled by the administrator.
• Update failed with
  • Error 3 or 11: When Chrome’s inbuilt updater fails to find the Update server to download the latest version.
  • Error 4 or 10: This happens while checking for updates with the message “Update check failed to start”
  • Error 7 or 12: This occurs when the download fails while checking for updates.
• Windows OS version is not supported.
• Google Chrome may not be able to keep itself updated.
• Any other errors that mention that “Update failed”

Since these aforementioned error codes are related to “Update Failure”, then they have common solutions and here they are:

Option 1 – Restart your computer

You need to restart your computer first and then try updating Chrome again. There are times when it’s only a temporary issue that can be fixed by simply restarting your computer.

Option 2 – Try checking antivirus programs, firewall, and parental control settings

If you have antivirus programs, a firewall installed in your computer, as well as parental controls, then any of these could be blocking you to download anything, including the update for Chrome. This is why you have to double-check and make sure that software updates aren’t being blocked by these programs. On the other hand, you can also try running the Network Troubleshooter as it can help you resolve any DNS or connectivity issues. To use it, follow the steps below.

• Open the Search bar on your computer and type in “troubleshoot” to open the Troubleshoot settings.
• Next, scroll down and select the “Network Adapter” option from the right pane.
• Then click on the Run Troubleshooter” button.
• After that, your computer will check for any possible errors and will pinpoint the root cause of the problem if possible.

Option 3 – Try to remove Proxy

Removing the Proxy might also help you in fixing the Chrome Update errors. Here’s how you can do it:

• Tap the Win + R keys to open the Run dialog box.
• Then type “inetcpl.cpl” in the field and hit Enter to pull up the Internet Properties.
• After that, go to the Connections tab and select the LAN settings.
• From there. Uncheck the “Use a Proxy Server” option for your LAN and then make sure that the “Automatically detect settings” option is checked.
• Now click the OK and the Apply buttons.
• Restart your PC.

Note: If you are using a third-party proxy service, you have to disable it.

Option 4 – Try to reset Winsock, TCP/IP & Flush DNS cache

Resetting Winsock, TCP/IP, and flushing DNS might help in resolving the Chrome Update errors just follow these steps:

• Right-click on the Start button and click on Command Prompt (administrator) so you can pull up an elevated Command Prompt.
• After that, execute each one of the commands listed below. And after you typed in one after the other, you have to hit Enter.

1. netsh winsock reset – type in this command to reset Winsock
2. netsh int ip reset resettcpip.txt – type in this command to reset TCP/IP
3. ipconfig /flushdns – type in this command to flush the DNS cache

• Next, restart your PC and check if the problem’s fixed.

Option 5 – Try to run the Chrome Cleanup tool

You might want to run Google Chrome’s built-in Malware Scanner & Cleanup tool as it could also help in getting rid of any unwanted ads, pop-ups, and even malware, as well as unusual startup pages, toolbars, and anything else that might overtake the network and could affect the performance of the browser.

Option 6 – Get rid of any conflicting browser extensions

• Open Chrome and press Alt + F keys.
• Go to More tools and click Extensions to look for any suspicious browser extensions or toolbars.
• Click the Recycle bin and select Remove.
• Restart Chrome and press Alt + F keys again.
• Proceed to On Startup and mark Open a specific page or set of pages.
• To check if the browser hijacker is still active, click Set pages, if it is active, overwrite the URL.

Option 7 – Reset Google Chrome

Resetting Chrome can also help you get rid of the error. Resetting Chrome will restore its default settings, disabling all the extensions, add-ons, and themes. Aside from that, the content settings will be reset as well and the cookies, cache, and site data will also be deleted. To reset Chrome, here’s what you have to do:

• Open Google Chrome, then tap the Alt + F keys.
• After that, click on Settings.
• Next, scroll down until you see the Advanced option, once you see it, click on it.
• After clicking the Advanced option, go to the “Restore and clean up option and click on the “Restore settings to their original defaults” option to reset Google Chrome.
• Now restart Google Chrome.

If you encounter an error message saying, “ERR SSL VERSION OR CIPHER MISMATCH” while visiting a website, then it is not primarily your fault as an end-user. In fact, it can happen on any website like Chrome, Edge, Firefox, and even Internet Explorer. Getting this error means that the website you are visiting is using an SSL certificate which your browser seems to be rejected because there is some issue with the certificate. It is also possible that the certificate that’s downloaded on your computer is corrupted or that your computer configuration for TSL/SSL is misconfigured. Here are the complete details of the error message:

“A secure connection cannot be established because this site uses an unsupported protocol, Error code ERR_SSL_VERSION_OR_CIPHER_MISMATCH”

To resolve the ERR_SSL_VERSION_OR_CIPHER_MISMATCH error, refer to the options given below and see which one works for you.

Option 1 – Try to access the website with the only HTTP

The first thing you can do is to try accessing the website using HTTP instead of HTTPS. If you can open the website using HTTP then it means that the problem is in the website itself. And if you are the website owner, you can check the following:

• Check if your website’s SSL certificate name is mismatched. Here you need to ensure that the name and alias of the websites match with the actual website URL where the certificate is installed.
• Second, check if your server is using the RC4 Cipher. If it is, then you need to fix that.

On the other hand, you may also check if your CDN also supports SSL since most of the CDN nowadays supports SSL. All you have to do is configure it correctly and it should be good to go.

Option 2 – Try enabling SSL 3 / TLS and disable QUIC Protocol

If you were using Google Chrome when you got the ERR SSL VERSION OR CIPHER MISMATCH error, then you need to follow the protocol fixes for SSL3/TLS and QUIC which are usually some of the reasons that cause the SSL version / Cipher Mismatch. It also has a few fixes for Windows 10 computer where you can clear the certificates and make sure that your computer date and time is in sync with your time zone and so on. If you were using Edge or Internet Explorer when you got the error, then you have to follow the steps below.

• Type “Internet” in the search box of your browser. After that, you should see the Internet Options from the search results.
• Next, open the Internet Properties window and switch to the Advanced tab and then scroll down to the Security section.
• From there, check the “Use TLS 1.1” checkbox as well as the “Use TLS 1.2” checkbox and then click OK to save the changes made.
• Restart the browser.

On the other hand, if you were using Firefox when you go the error, here’s what you have to do.

• Open Firefox and in the address bar, type “about:config” and hit Enter.
• If a warning appears, just click on the “I accept the risk!” button to proceed.
• Next, type in “TLS” in the search field and hit Enter.
• Then look for “security.tls.version.min” and double click on it and set its integer value to 3 to force the protocol of TLS 1.3.
• Now click OK and restart Firefox and do the same thing with SSL.

When trying to run Computer Management, or when running mmc.exe or compmgmt.msc from a command prompt you get the error that the application has been blocked for your protection then keep reading in order to solve the issue. This is a permission issue where if a regular user tries to run such system tools will result in saying that it has been blocked. Along with this, you may have a Group Policy issue. This can be fixed, but you will need admin permission to achieve it. It’s because when they are run from the command prompt with elevated privileges, it works.

1. Change Group Policy Settings

   If your account is an admin account, and you are still facing the issue, then change the group policy settings: Open Group Policy Settings by typing gpedit.msc in the run prompt followed by pressing ENTER Navigate to User Configuration > Administrative Templates > Windows Components > Microsoft Management Console > Restricted/Permitted snap-ins Locate Computer Management policy, and double click to open it Enable it, exit Group Policy. When Enabled: The snap-in is permitted and can be added into the Microsoft Management Console or run from the command line as a standalone console. When Disabled: The snap-in is prohibited and cannot be added into the Microsoft Management Console or run from the command line as a standalone console. An error message is displayed stating that the policy is prohibiting the use of this snap-in.

2. Temporarily disable UAC

   UAC is the user access control panel, and if you need to run the command right away, you can choose to disable it for some time. Click on the Start button, and then type UAC to find the User Account Control Settings. Click to open, and then slide down the notification setting at the bottom. It will temporarily allow launching the application as there is no check. However, make sure to switch to default once you are done.

If you encounter the CLOCK_WATCHDOG_TIMEOUT Blue Screen of Death error while using your Windows 10 computer then it is most likely caused by a specified processor which is not processing interrupts. This occurs when the processor is deadlocked or nonresponsive. Specifically, this kind of Stop error occurs when the processor is having a hard time with the cooperation of its threads and cores. The threads are the tasks performed by cores and some cores can have many threads at the same time. And this is where the problem begins – one thread is waiting for an adequate response from another thread or one kernel is waiting for a response from another kernel and those responses are not coming. In other words, when the processor is unable to continue the processing of tasks since its resources are occupied and are interdependent to get free, such a state is called Deadlock. The CLOCK WATCHDOG TIMEOUT bug check has a value of 0x00000101 which means that an expected clock interrupt on a secondary processor, in a multiprocessor system, was not received within the allocated interval. To troubleshoot the problem, you can check out the possible fixes provided below but before you proceed, make sure that you boot your computer into Safe Mode with Networking only.

Option 1 – Undo or disable overclocking if you have overclocked your system

• Go to the Start Menu and open Settings.
• Next, select Update and Security and go to the Recover tab.
• From there, click on Restart now in Advanced startup. This will restart your computer.
• Once you’re in the Advanced startup, go to Troubleshoot and then select the Advanced Options.
• From there, select the UEFU Firmware Settings.
• Now click on Restart. Once your computer has restarted, it will automatically open BIOS.
• From the BIOS, go to the Advanced tab and navigate to Performance and then look for Overclocking.
• Once you’ve found Overclocking, make sure that it is disabled. If it’s not, then disable it and then save the changes made by tapping the F10 key.
• Start your computer normally and check if the CLOCK_WATCHDOG_TIMEOUT 0x00000101 error is now fixed.

Option 2 – Try running the Memory Diagnostic Tool

The Memory Diagnostic tool in windows can help resolve the CLOCK_WATCHDOG_TIMEOUT 0x00000101 Blue Screen error by checking and automatically fixing any memory-based issues. To run it, refer to these steps:

• Tap the Win + R keys to open Run and type mdsched.exe and hit Enter to open the Windows Memory Diagnostic Tool.
• After that, it will give two options such as:
  • Restart now and check for problems (Recommended)
  • Check for problems the next time I start my computer
• Once your computer has restarted, perform a basic scan or you could also go for the “Advanced” options such as “Test mix” or “Pass count”. Simply tap the F10 key to start the test.

Option 3 – Try to rollback, update or disable drivers

The next thing you can do to fix the CLOCK_WATCHDOG_TIMEOUT 0x00000101 Stop error is to roll back, or update, or disable device drivers. It is most likely that after you updated your Windows computer that your driver also needs a refresh. On the other hand, if you have just updated your device drivers then you need to roll back the drivers to their previous versions. Whichever applies to you, refer to the steps below.

• Open the Devices Manager from the Win X Menu.
• Then locate the device drivers and right-click on them to open the Properties.
• After that, switch to the Driver tab and click on the Uninstall Device button.
• Follow the screen option to completely uninstall it.
• Finally, restart your computer. It will just reinstall the device drivers automatically.

Note: You can install a dedicated driver on your computer in case you have it or you could also look for it directly from the website of the manufacturer.

Option 4 – Try running the Blue Screen Troubleshooter

The Blue Screen troubleshooter is a built-in tool in Windows 10 that helps users in fixing BSOD errors like CLOCK_WATCHDOG_TIMEOUT 0x00000101. It can be found on the Settings Troubleshooters page. To use it, refer to these steps:

• Tap the Win + I keys to open the Settings panel.
• Then go to Update & Security > Troubleshoot.
• From there, look for the option called “Blue Screen” on your right-hand side and then click the “Run the troubleshooter” button to run the Blue Screen Troubleshooter and then follow the next on-screen options. Note that you might have to boot your PC into Safe Mode.

Option 5 – Try to disconnect or disable newly installed hardware

In this option, you will have to disable or remove the hardware you’ve just installed recently since external devices could be the one that’s causing the Blue Screen of Death error to appear. To do that, just disconnect any external device that’s connected to your computer physically and then check if it fixes the CLOCK_WATCHDOG_TIMEOUT Blue Screen error.

Option 6 – Troubleshoot the BSOD error in Clean Boot State

You can also troubleshoot the Blue Screen error in a Clean Boot state. There are times when third-party applications cause BSOD errors. Putting your computer in this state can help you identify which program is the culprit and thus isolates the problem. In a Clean Boot state, your computer will start using only the pre-selected minimal set of drivers and startup programs. Note that you have to disable and enable one process at a time.

• Log onto your PC as an administrator.
• Type in MSConfig in the Start Search to open the System Configuration utility.
• From there, go to the General tab and click “Selective startup”.
• Clear the “Load Startup items” check box and make sure that the “Load System Services” and “Use Original boot configuration” options are checked.
• Next, click the Services tab and select the “Hide All Microsoft Services” check box.
• Click Disable all.
• Click on Apply/OK and restart your PC. (This will put your PC into a Clean Boot State. And to configure Windows to use the usual startup, just simply undo the changes.)
• From there, start to isolate the problem by checking which one of the programs you installed recently is the root cause of the problem.

Option 7 – Try to update the BIOS

Updating the BIOS can help you fix the CLOCK_WATCHDOG_TIMEOUT BSOD error but as you know, BIOS is a sensitive part of a computer. Even though it is a software component, the functioning of the hardware depends on it largely. Thus, you must be careful when modifying something in the BIOS. So if you don’t know much about it, it’s best if you skip on this option and try the other ones instead. However, if you are well-versed in navigating the BIOS, then follow the steps below.

• Tap the Win + R keys to open the Run dialog box.
• Next, type “msinfo32” in the field and press Enter to open System Information.
• From there, you should find a search field on the bottom where you have to search for the BIOS version and then press Enter.
• After that, you should see the developer and version of the BIOS installed on your PC.
• Go to your manufacturer’s website and then download the latest version of BIOS on your computer.
• If you are using a laptop, make sure that you keep it plugged in until you have updated the BIOS.
• Now double click on the downloaded file and install the new BIOS version on your computer.
• Now restart your computer to apply the changes made.