KB5042421: CrowdStrike issue impacting Windows endpoints causing an 0x50 or 0x7E error message on a blue screen (2024)

For information about this issue with CrowdStrike on Windows servers, see KB5042426.

Summary

Microsoft has identified an issue impacting Windows endpoints that are running the CrowdStrike Falcon agent.These endpoints might encounter error messages 0x50 or 0x7E on a blue screen and experience a continual restarting state.

We have received reports of successful recovery from some customers attempting multiple restart operations on affected Windows endpoints.

We are working with CrowdStrike to provide the most up-to-date information available on this issue. Please check back for updates on this ongoing issue.

Resolution

Important:We have released a USB tool to help automate this manual repair process. For more information, seeNew recovery tool to help with CrowdStrike issue impacting Windows devices.

To resolve this issue, follow these instructions for your version of Windows.

Windows 11Windows 10

Hold the power button for 10 seconds to turn off your device and then press the power button again to turn on your device.
On the Windows sign-in screen, press and hold theShift key while you selectPower >Restart.
After your devicerestarts to theChoose an optionscreen, selectTroubleshoot.
On the Troubleshoot screen, selectAdvanced options>Startup Settings> Enable safe mode.
Restart your device.
NoteYou may be asked to enter yourBitLocker recovery key. When the device restarts, continue pressing F4 and then it will log you in to safe mode. Please note, for some devices, you need to press F11 to log in through safe mode.
Once in safe mode, right-click Start, clickRun,typecmdin the Open box, and then click OK.
If your system drive is different than C:\, type C: and then press Enter.This will switch you to the C:\ drive.
Type the following commandand then press Enter:

CD C:\Windows\System32\drivers\CrowdStrike

Note In this example, C is your system drive. This will changeto the CrowdStrike directory.
Once in the CrowdStrike directory, locate the file matching “C-00000291*.sys”. To do this, typethe followingcommand and then press Enter:

dir C-00000291*.sys
Permanently delete the file(s) found. To do this,type the followingcommand and then press Enter.

del C-00000291*.sys
Manually search for any files that match “C-00000291*.sys” and delete them.
Restart your device.

Hold the power button for 10 seconds to turn off your device and then press the power button again to turn on your device.
On the Windows sign-in screen, press and hold theShiftkey while you selectPower>Restart.
After your devicerestarts to theChoose an optionscreen, selectTroubleshoot.
See Also
Tastenhandys sind wieder im Trend – das sind die beliebtesten Modelle Joe Biden wants to pass the baton to Kamala Harris. Here's how that might work The Handy Review - Must Read This Before Buying The Handy with Fleshlights - Which Fleshlights/Onaholes fit exactly & how? - Men's Pleasures
On the Troubleshoot screen, selectAdvanced options>Startup Settings>Enable safe mode.
Restart your device.
NoteYou may be asked to enter yourBitLocker recovery key.
When the device restarts, continue pressing F4 and then it will log you in to safe mode.
Once in safe mode, right-click Start, clickRun,typecmdin the Open box, and then clickOK.
If your system drive is different than C:\, type C: and then press Enter.This will switch you to the C:\ drive.
Type in the following command and then press Enter:

CD C:\Windows\System32\drivers\CrowdStrike

NoteIn this example C is your system drive.This will change to the CrowdStrike directory.
Once in the CrowdStrike directory, locate the file matching “C-00000291*.sys”. To do this, typethe followingcommand and then press Enter:

dir C-00000291*.sys
Permanently delete the file(s) found. To do this,type the followingcommand and then press Enter.

del C-00000291*.sys
Manually search for any files that match “C-00000291*.sys” and delete them.
Restart your device.

Recovery methods

If you receive the Windows Recovery screen, use one of the following methods to recover your device.

Method 1: Use Enable safe mode

Windows 11Windows 10

Hold the power button for 10 seconds to turn off your device and thenpress the power button again to turn on your device.
On the Windows sign-in screen, press and hold theShiftkey while you selectPower >Restart.
After your device restarts to theChoose an optionscreen, selectTroubleshoot>Advanced options>Startup Settings>Enable safe mode. Then, restart your device.
NoteYou mightbe asked to enter yourBitLocker recovery key. When the device restarts, continue pressing F4 and then it will log you in to safe mode. Please note, for some devices, you need to press F11 to log in through safe mode.
If the screen asks for a BitLocker recovery key,useyour phone andlog ontohttps://aka.ms/aadrecoverykey.Log on withyour Email ID and domain account password to find the BitLocker recovery key associated with your device.
To locate your BitLocker recovery key, click Manage Devices > View Bitlocker Keys > Show recovery key.
Select the name of the device where you see the BitLocker prompt.In the expanded window,select View BitLocker Keys. Go back to your device and input the BitLocker key that you see on your phone or secondary device.
When the device restarts, continue pressing F4 and then it will log you in to safe mode.
Once in safe mode, right-click Start, clickRun,typecmdin the Open box, and then clickOK.
If your system drive is different than C:\, type C: and then pressEnter.This will switch you to the C:\ drive.
Type the following command and then press Enter:

Tip: CD C:\Windows\System32\drivers\CrowdStrike

NoteIn this example, C is your system drive.This will changeto the CrowdStrike directory.
Once in the CrowdStrike directory, locate the file matching “C-00000291*.sys”. To do this, typethe followingcommand and then press Enter:

dir C-00000291*.sys
Permanently delete the file(s) found. To do this,type the followingcommand and then press Enter.

del C-00000291*.sys
Manually search for any files that match “C-00000291*.sys” and delete them.
Restart your device.

Hold the power button for 10 seconds to turn off your device and then press the power button again to turn on your device.
On the Windows sign-in screen, press and hold theShiftkey while you selectPower >Restart.
After your device restarts to theChoose an optionscreen, selectTroubleshoot>Advanced options>Startup Settings>Enable safe mode. Then restart your device again.
NoteYou mightbe asked to enter yourBitLocker recovery key. When the device restarts, continue pressing F4 and then it will log you into safe mode. Please note, for some devices, you need to press F11 to log in through safe mode.
If the screen asks for a BitLocker recovery key, then useyour phone andlog on tohttps://aka.ms/aadrecoverykey.Log on with your Email ID and domain account password to find the bit locker recovery key associated with your device.
To locate your BitLocker recovery key, click Manage Devices > View Bitlocker Keys > Show recovery key.
Select the name of the device where you see the BitLocker prompt.In the expanded window, select View BitLocker Keys. Go back to your device and input the BitLocker key that you see on your phone or secondary device.
When the device restarts, continue pressing F4 and then it will log you in to safe mode.
Once in safe mode, right-click Start, clickRun,typecmdin the Open box, and then clickOK.
If your system drive is different than C:\, type C: and then press Enter.This will switch you to the C:\ drive.
Type in the following command and then press Enter:

Tip: CD C:\Windows\System32\drivers\CrowdStrike

NoteIn this example, C is your system drive.This will change to the CrowdStrike directory.
Once in the CrowdStrike directory, locate the file matching “C-00000291*.sys”. To do this, typethe followingcommand and then press Enter:

dir C-00000291*.sys
Permanently delete the file(s) found. To do this,type the followingcommand and then press Enter.

del C-00000291*.sys
Manually search for any files that match “C-00000291*.sys” and delete them.
Restart your device.

Method 2: Use System Restore

Windows 11Windows 10

Hold the power button for 10 seconds to turn off your device and then press the power button again to turn on your device.
On the Windows sign-in screen, press and hold theShiftkey while you selectPower >Restart.
After your device restarts to theChoose an optionscreen, selectTroubleshoot>Advanced options>System Restore.
If the screen asks for a BitLocker recovery key, useyour phone andlog on tohttps://aka.ms/aadrecoverykey.Login with your email id and domain account password to find the bit locker recovery key associated with your device.
To locate your BitLocker recovery key, click Manage Devices > View Bitlocker Keys > Show recovery key.
Select the name of the device where you see the BitLocker prompt.In the expanded window, select View BitLocker Keys. Go back to your device and input the BitLocker key that you see on your phone or secondary device.
Click Nexton System Restore.
Select the Restore option in the list, clickNext, and then clickFinish.
Click Yesto confirm the restore.
NoteThis will perform just the Windows system restore and personal data should not be impacted. This process might take up to 15 minutes to complete.

Hold the power button for 10 seconds to turn off your device and then press the power button again to turn on your device.
On the Windows sign-in screen, press and hold theShiftkey while you selectPower >Restart.
After your device restarts to theChoose an optionscreen, selectTroubleshoot>Advanced options>System Restore.
If the screen asks for a BitLocker recovery key, useyour phone andlog on tohttps://aka.ms/aadrecoverykey.Log in with your Email ID and domain account password to find the bit locker recovery key associated with your device.
To locate your BitLocker recovery key, click Manage Devices > View Bitlocker Keys > Show recovery key.
Select the name of the device where you see the BitLocker prompt.In the expanded window, select View BitLocker Keys. Go back to your device and input the BitLocker key that you see on your phone or secondary device.
Click Nexton System Restore.
Select the Restore option in the list, click Next, and then clickFinish.
Click Yesto confirm the restore.
NoteThis will perform just the Windows system restore and personal data should not be impacted. This process might take up to 15 minutes to complete.

Contact CrowdStrike

If after following the above steps, if you still experience issues logging into your device, please reach out to CrowdStrike for additional assistance.

References

Start your PC in safe mode in Windows

The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. We make no warranty, implied or otherwise, about the performance or reliability of these products.

We provide third-party contact information to help you find technical support. This contact information may change without notice. We do not guarantee the accuracy of this third-party contact information.

KB5042421: CrowdStrike issue impacting Windows endpoints causing an 0x50 or 0x7E error message on a blue screen (2024)

FAQs

How to fix blue screen of death? ›

The simplest fix is to repeatedly reboot your computer, said iFixit CEO Kyle Wiens. Try restarting up to 15 times to see if anything changes, he suggested. If that doesn't work, you can restore your computer to a version before the update.

Why does Windows 10 keep crashing Blue Screen? ›

These errors can be caused by both hardware and software issues. If you added new hardware to your PC before the Blue Screen error, shut down your PC, remove the hardware, and try restarting. If you're having trouble restarting, you can start your PC in safe mode.

Learn More ›

Why is it called the blue screen of death? ›

A BSOD functionally renders an affected system nonoperational until the issue is resolved with some form of intervention by the user. The term blue screen of death is a reference to the color of a user's system screen when the BSOD is triggered.

Show Me More ›

Can Blue Screen of Death go away on its own? ›

Windows has a few methods for automatically fixing the BSoD. In some cases, the crash may only occur once. However, it's never wise to ignore the problem. If Windows can't solve the problem itself, Fortect is an excellent tool for repairing your system.

Is Blue Screen of Death unfixable? ›

The Blue Screen of Death is a critical error, but the good news is it's not unfixable. Microsoft offers valuable tips of its website, including a tip to remove any recently added hardware and restarting the device.

Get More Info ›

Why does my PC keep blue screening? ›

Any number of problems typically triggers the blue screen on the PC. Software conflicts, hardware problems, driver inconsistencies, and malware infections can all contribute to the BSOD. Even during system updates, if Windows encounters problems correctly updating the system, it can lead to the BSOD.

Read The Full Story ›

Why is Windows 11 blue screen with sad face? ›

Furthermore, you will only see a blue background with a sad kaomoji and insufficient information to determine the reason for the problem. However, the issue can usually be narrowed to a buggy update, device driver, compatibility issues with a specific app, or a piece of hardware that needs replacing.

Learn More Now ›

How to check what caused a blue screen? ›

In Windows, you can troubleshoot blue-screen information using the Action Center. In Windows 10 and Windows 11, head to Control Panel > Security and Maintenance. In Windows 7, head to Control Panel > System and Security. In the "Maintenance" section, you'll be able to check for solutions to existing problems.

See Details ›

Should I be worried about a blue screen Windows 10? ›

An occasional BSOD that you never see again could be harmless. However, regular blue screens can be problematic and frustrating because they may indicate a deeper malaise and force you to lose data upon every reboot.

View Details ›

How much does it cost to fix a blue screen? ›

Here are some average prices when it comes to fixing common PC repair issues: Blue or blank screen: Around $150. Slow overall performance: Around $210.

View Details ›

How to scan for damaged system files? ›

The sfc /scannow command will scan all protected system files, and replace corrupted files with a cached copy that is located in a compressed folder at %WinDir%\System32\dllcache. The %WinDir% placeholder represents the Windows operating system folder. For example, C:\Windows.

Does BSOD damage your computer? ›

Can a BSoD damage my computer permanently, and how can I protect against it? Generally, a BSoD itself won't damage your computer.

Why is blue screen scary? ›

The Blue Screen of Death usually occurs when your computer encounters a critical error that it can't recover from. This could be due to hardware or software issues, such as corrupt drivers, faulty memory, or incompatible software installations.

Keep Reading ›

Is blue screen of death serious? ›

An occasional BSOD that you never see again could be harmless. However, regular blue screens can be problematic and frustrating because they may indicate a deeper malaise and force you to lose data upon every reboot.

Tell Me More ›

How do I turn off the blue screen of death? ›

Press the Windows Key + R, type in SystemPropertiesAdvanced.exe and press Enter. Click on Settings under Startup and Recovery. Uncheck Automatically restart. Verify Active memory dump is selected under Write debugging information.

Is there a way to force a blue screen of death? ›

You can do this by holding down the furthest most right "Control" key then pressing the "Scroll Lock" key twice. Once this is completed, a blue screen should pop up. If you are using Windows 8 or later, the Blue Screen is slightly different.

See Details ›

Can resetting PC fix blue screen of death? ›

Blue screen errors are pesky errors that indicate a critical failure that the system can't handle, causing it to crash. A system reset or a hard reset is done to resolve any serious errors or issues like, in this case, a BSoD impeding our work. However, there are times when resetting a Windows PC doesn't help much.

Find Out More ›