Windows 10 and 11 had a number of issues at the time when it was first released.

Some errors were solved but there was plenty of them which werent.

One of those errors is associated with thewindows 10 blue screen error0xc000021a.

This error can crash all active programs and force your PC to restart to avoid permanent damage.

Both files are one of important system files, Winlogon.exe is responsible for managing the login and logout processes.

Csrss.exe belongs to Microsoft Client or Server Runtime Server Subsystem.

It states that Your PC ran into a problem and needs to restart.

This error appears inside a blue screen of death.

So,It may have some serious issues damaging the internal structure of Windows OS.

This error also persists even after restarting the PC.

In response, the operating system switches to kernel mode.

Microsoft Windows cannot run without WinLogon or CSRSS.

Aside from The 0xC000021A error can occur if Winlogon.exe or Csrss.exe stops working.

And startup repair may help to fix this issue.

To perform startup repair on windows 10 and 8.1 First Access Advanced Startup Option.

On the Advanced options screen as shown below opt for startup repair.

If Startup Repair can fix the problem, it will do so without any intervention.

It will then restart the system and boot normally.

check the problem is solved if still you face the same problem follow the next steps.

Now on the next screen press the F6 key to boot into Safe Mode with Command Prompt.

D is my windows installed volume.

This will take some time to complete wait until 100 % complete.

After that additionally, perform the below commands one by one.

cd D:WindowsWinSxS

move pending.xml pending.old

This will work if a pending.xml has been created.

Now after that restart the system and when started next timewindows 10 blue screen error 0xc000021acan be solved.

This is the best working solution for most windows users if you still getting error follow the next step.

This tool will detail and potentially fix any unexpected corruption, returning the system to a good working state.

Do not terminate the Command Prompt window until the verification is 100% complete.

Disable driver signature enforcement

Restart the PC from Windows by holding the Shift and selecting Restart.

When the options screen opens, select Troubleshoot.

This way, you will be able to access advanced tools.

Select Advanced Option on the next screen.

When the startup screen opens, press F7 (Disable driver signature enforcement).

After that, the PC will restart.

Checkwindows 10 blue screen error 0xc000021awill be solved otherwise follow the next step.

for this, you have to uninstall the program, then evaluating your system.

First, ensure you have administrative rights to make changes or uninstall any utility.

Lets follow the steps to do this.

so To determine whether or not this is the case, you gotta test your RAM.

Now select Restart now and check for problems.

It will start your PC and diagnose your memory problems.

Let the program finish and if any error is found, it will be reported.

If this is the case, then its time to replace the erring memory module.

Fix Corrupted Registry Files

To fix corrupted registry files you have to use a registry cleaner.

There are lots of paid and free versions of registry cleaner on the internet.

it’s possible for you to download any of them.

Restoring Windows back to an earlier point in time.

Restore Points proves to be very useful in situations like this.