[Solved] BSOD Critical Process Died 

The Critical Process Died error, identified by bugcheck code 0x000000EF, is a BSOD error that occurs when one of the critical Windows processes closes abruptly. Critical processes are essential Windows process that is required for the proper functioning of Windows.

The system files that run critical processes include conhost.exe, csrss.exe, logonui.exe, services.exe, winlogon.exe, and so on. Whenever one of these processes gets corrupted, your system will crash itself to prevent further corruption.

Sometimes the BSOD happens randomly after logging in, while in most situations, it happens repeatedly before you can even log in, causing your system to enter a BSOD restart loop. Here, I will provide possible solutions for both of these situations.

First, Identify the Cause

This BSOD error can occur due to issues with several software or hardware components. So, if you want to resolve it effectively, it’s better to identify the underlying cause of the error.

If you can successfully narrow it down, you can simply troubleshoot the relevant component. Otherwise, you need to go through all the possible solutions below.

Check if You can Boot in Safe Mode

The first thing you should do is check if you can boot in safe mode regardless of whether you are getting stuck in a BSOD restart loop or not.

1. First, you need to access the Advanced Startup or Windows Recovery Environment (WinRE). You can do so in either of the following ways:
   • Click on the power button on the Start menu or the login screen. Then, press the Shift key while clicking on the Restart button to boot to WinRE. You may need to click on Restart anyway as well.
   • If you can’t access the login screen due to BSOD restart loops, after the third crash, your computer will load the Startup Repair screen. Here, click on Advanced options to get to WinRE.
   • You can manually force shutdown your computer and then power it up again four times. You can perform a force shutdown by pressing and holding the power button for a few seconds.
2. Then, go to Troubleshoot > Advanced Options > Startup Settings and select Restart.
3. After the reboot, press on 5 or F5 to boot into safe mode with networking.
   

Depending on the cause of the error, two things may happen:

• You can get into safe mode and not get this BSOD.
• You can’t enter into safe mode, or you can do so, but the BSOD still occurs.

If you have installed any new hardware recently, try troubleshooting any potential errors due to this hardware in either case. 

Other than that, if you can boot in safe mode without any BSODs, resolving the driver issues, system corruption, application conflicts, update errors, and malware infections should resolve the error.

But if you get this error in the safe mode, it usually indicates serious issues with your operating system. You may need to reinstall Windows altogether in this scenario.

Check Event Viewer

While analyzing crash dumps is usually the best way to check the cause of a BSOD error, it won’t be as effective in this case. This BSOD happens as a result of a cascading failure where many interconnected components fail at once due to one of the components failing. So, the crash dumps may not point to the exact cause of the error in most cases.

So checking the event logs in the Event Viewer is the most effective way to narrow down the cause of this BSOD error.

1. Open the Run command.
2. Type eventvwr and press Enter to load the Event Viewer.
3. Go to Windows Logs > System.
4. Click on Filter Current Log. 
   
5. Type 1001 in the <All Event ID> textbox and click OK.
   
6. Note the timestamp of the bugcheck and then click Clear Filter.
7. Go to that timestamp and check all the events during and just before that time.

In most cases, faulty hardware or driver is responsible. If so, you’ll see “WHEA…” in the event’s source column. The details should point to the hardware. In such cases,

• Try troubleshooting their driver issues by updating and uninstalling them (see the solutions below).
• Check if the device is connected properly with the motherboard. 
• Try looking at user forums for any incompatibility issues and possible patches.
• If you can’t resolve the error after these, the device is likely damaged. You’ll need to take the device or your computer to a hardware expert for repair or replacement.

It is difficult to detect if the cause is not a driver or hardware. So you should try performing all the solutions in this article.

Troubleshoot New Hardware Additions

If this error started cropping up after you installed some new hardware into your system, the hardware may be causing the issue. You can perform the following actions to confirm as well as try to resolve this issue.

• Check on the manufacturer’s website and official forums for any issues with the device and if there are any patches. Also, check the compatibility with your Windows version.
• If your current BIOS version does not support them, try updating the BIOS. You can check on the official website for the minimum BIOS version requirements.
• Update their drivers. Try downloading the driver installer directly from the manufacturer’s website and install it.
• If the motherboard or the new hardware comes with their dedicated diagnostic utilities, you can try running those as well.
• You can also open the computer, remove those devices and check if you still encounter BSOD errors.

If the hardware still does not work well with your computer or operating system, you’ll need to replace it with a more compatible device.

Update Device Drivers

Outdated or corrupt drivers are responsible for many system problems, including BSODs. Since you can get the error due to hardware issues, I recommend keeping your drivers up to date.

1. Open Run by pressing Windows key + R.
2. Type devmgmt.msc and press Enter to load the Device Manager.
3. Expand all the categories.
4. If there are any devices that show an exclamation mark, right-click on them and select Update driver > Search automatically for drivers.
   

Reinstall Device Drivers

If the device drivers are already updated or updating them still doesn’t resolve the issue, you need to reinstall the drivers. It’s better to uninstall all previous driver software at the same time to avoid any conflicts with the newer drivers.

1. Open the Device Manager if you closed it earlier.
2. On the menu bar, select View > Show hidden devices.
   
3. Expand all the categories.
4. Right-click on the grayed out device drivers that show and choose Uninstall device > Uninstall.
   
5. Uninstall the device driver with the error (exclamation icon) as well.
6. Now, open Run.
7. Type cleanmgr and press Enter to open Disk Cleanup.
8. Set the drop-down list to the system drive (usually C:) and click OK.
9. Click Clean up System Files and select the system drive again.
   
10. Check Device driver packages from the list.
11. Uncheck the other options you don’t wish to remove and hit OK.
    
12. Go back to the Device Manager.
13. Right-click on the computer name and select Scan for hardware changes to reinstall the drivers you uninstalled in step 5.

Repair Corrupt System Files

Corrupt system components can also cause critical processes to end abruptly in various ways. So, you need to scan for and repair any possible system corruption. You can use the System File Checker (SFC), Deployment Image Servicing and Management (DISM), and the Disk Checking utility (CHKDSK) for this purpose.

1. Open Run.
2. Type cmd and press Ctrl + Shift + Enter to open the Elevated Command Prompt.
3. Type the commands below and press Enter after each:
   • dism /online /cleanup-image /restorehealth
   • sfc /scannow
   • chkdsk C: /r /x
     
4. Type Y and press Enter after the chkdsk command. Then, restart your computer.

If you get stuck in a BSOD restart loop, you can try running these utilities from the Advanced Startup.

1. Go to the Windows Recovery Environment.
2. Select Troubleshoot > Advanced Options > Command Prompt.
3. Type the following commands and press Enter after each:
   • bcdedit (check the drive letter of osdevice under Windows Boot Loader. WinRE will reassign the drive letter for the system drive, so it may no longer be C:.)
   • DISM /Image:E: /Cleanup-Image /RestoreHealth
   • SFC /Scannow /offbootdir=E:\ /offwindir=E:\windows
   • chkdsk E: /r
     

Check for Malware Infection

Some malware scripts can infect system files and cause critical processes to fail. So it’s worth performing a full scan of your computer to look out for such threats. To do so using Virus & threat protection, follow these steps.

1. Open Run.
2. Type ms-settings:windowsdefender and press Enter to open Windows Security.
3. Go to Virus & threat protection and select Scan options.
4. Check Full scan. Then, select Scan now.
   

If you can’t sign in to your account, you need to boot into Safe mode and then run Windows Defender from Command Prompt.

1. Open Run on Safe mode.
2. Type cmd and press Enter to open Command Prompt.
3. Type cd C:\ProgramData\Microsoft\Windows Defender\Platform\
4. Use the command dir to check the contents.
5. Change the directory to the folder with the highest number. For example, cd 4.18.2203.5-0.
6. Then, type MpCmdRun -Scan -ScanType 2 and press Enter.
   

Check Recently Installed Applications

Some applications can also conflict with your drivers or system processes and cause this error.

If you recently installed any applications in your computer and this error started occurring after that time, one of those apps is likely causing the issue.

Check dedicated forums for the apps to see if other users are also experiencing the same issue. If so, you need to uninstall it and then install a previous version or wait for a future update. To uninstall the app,

1. Open Run.
2. Type appwiz.cpl and click OK to open Programs and Features.
3. Select the application and click Uninstall.
   
4. Follow the given instructions.

You can also troubleshoot in clean boot mode if you need to determine which process is causing such conflicts.

1. Open Run.
2. Type msconfig and click OK to load System Configuration.
3. Head over to the Services tab.
4. Tick Hide all Microsoft services and choose Disable all.
   
5. Press the key combination, Ctrl + Shift + Esc to launch the Task Manager. Here, go to the Startup tab.
6. Look for all services whose Status says Enabled. Click on them and select Disable.
   
7. Now, restart your computer. It will start in clean mode where all those services and apps are not running. 

If you still keep getting BSODs, it means that none of these services or startup apps were responsible. So, you should revert all the changes by enabling them, restart your device, and then move on to the next method.

But if you don’t encounter the BSOD error even after using your computer for a while, it means that one of the processes you disabled earlier definitely was responsible for the error. Here, you need to check them to narrow down the cause.

1. You need to selectively enable some services or apps, restart again, and look out for the BSOD.
2. If the error occurs, the culprit is within the enabled processes. Otherwise, it sits with the rest of the processes.
3. Keep selectively enabling/disabling these processes and reboot every time until you can isolate the exact service or app causing the conflicts. 
4. After determining the cause, you can disable it or uninstall its root application to resolve your issue.

Update or Rollback Windows

Some updates can introduce undesirable bugs in your system that affect the critical system files.

So, if this BSOD started happening after a system update, you need to report this bug to Microsoft and wait for them to provide bug fixes or patches.

Meanwhile, it’s best to uninstall the problematic update and roll back your system to a previous version. It’s also better to pause updates for some time to avoid this update from automatically installing again.

1. Open Programs and Features.
2. Select View installed updates.
3. Search for the most recent update under Microsoft Windows.
4. Select the update and then click on Uninstall > Yes.
   
5. Press Windows key + I to open Settings.
6. Go to Windows Update or Update & Security > Windows Update.
7. Select Pause for 1 week or Pause updates for 7 days.
   

To rollback the update from Advanced Startup,

1. Go to the Windows Recovery Environment.
2. Select Troubleshoot > Advanced Options > Uninstall Updates.
3. Choose Uninstall latest quality update or Uninstall latest feature update depending on the latest update. Feature upgrade means major updates that directly change the Windows version like Windows 11 or 22H2.
   
4. Follow the on-screen instructions.
5. After completing the process, restart the computer and see if you can log in to your account without encountering the BSOD.

Then, check if Microsoft rolls out any new updates regularly. After Microsoft provides an update that addresses this issue, you can resume your updates.

1. Go to Windows Update Settings.
2. Click Resume updates.
3. Then, select Check for updates and then Install now if the update settings doesn’t show any available updates or just Install now if it does.
   

Perform System Restore

If the previous solutions failed, you could try restoring your system back to the state when this error hadn’t started occurring yet. 

You will need an appropriate restore point of that time to revert all the changes that occurred from that point onwards.

1. Open Run.
2. Type rstrui and press Enter to open the System Restore utility.
3. Select a suitable restore point and go through the given instructions.
   

To perform System Restore from Advanced Startup,

1. After getting to WinRE, select Troubleshoot > Advanced options > System Restore.
   
2. Then, select the restore point and follow the on-screen instructions.

If restoring the system does not help or you don’t have a suitable restore point, your only remaining option is to reinstall Windows.