Windows 10: Black Screen After Login, Possibly Due to KB4345421 (Windows 10 Home)

I installed KB4345421 on two Win10 Home computers recently. One install worked fine, but on the other one, I got a black screen after logging in. Creating a new account did not solve the problem - it started the account setup, then displayed "It's taking a bit longer than expected, but we'll get there as fast as we can". The next time I checked the computer, the new account was also showing a black screen.


I was able to get into Task Manager through Ctrl-Alt-Delete. I noticed that Explorer was not running, and started it from the Task Manager -> File menu. Explorer appeared to start, but then disappeared. I was able to start various other applications. I ran sfc /scannnow which failed with "Windows Resource Protection could not perform the requested operation." Running chkdsk and resetting the winsxs permissions did not allow sfc to complete.


I was able to uninstall KB4345421 from the command line - login works properly now and sfc /scannow completes without errors.


I had a look at the Application Event Log around the time of the reboot prior to uninstalled KB4345421. There are a lot of errors relating to C:\Windows\System32\twinui.pcshell.dll not being accessible and Explorer.exe/svchost.exe_WpnUserService failing due to an 0xc0000005 error in ntdll.dll. My best guess is that KB4345421 did not install properly. We will see what happens the next time Windows Update tries to install it.


Regards, Norbert

:)

 

black screen

Hi Bart,

It is possible that you're experiencing black screen due to corrupted system files. To assist you better, we'd like to gather more information:

• Are you getting any error messages?
• What happen when you tried to login?
• What troubleshooting steps have you done so far?

In the meantime, we suggest that you follow the steps in this
article to troubleshoot black screen errors. You can choose which situation you're experiencing the error and perform the instructions.

Let us know if you need further assistance.

 

Black screen error

Hello,

There are several reasons why you are facing a black screen issue. One of these is due to outdated or incorrect device drivers. For us to figure out what's causing this, provide more details by answering the listed questions:

• Can you confirm to us if you are using a laptop or a computer?
• Have you made any recent changes to your device prior to this happening?
• What exactly were you doing when the error occurred?
• Have you tried any troubleshooting steps to resolve this? If yes, specify all of the steps that you have done.

As an initial part of troubleshooting, we suggest following the steps given on this article:

Troubleshoot black screen or blank screen errors. This will help you diagnose and rectify most of the known black screen concerns.

We will wait for your response.

 

Black Screen with Pointer

Hi Costa,

Thanks for posting your query on Microsoft Community. We will surely help you with simple steps to resolve your issue.

To assist you better, please provide few details.

• 
  Is the black screen with courser appears after login or before login?
  
• 
  Did you make any changes to the computer, prior to the issue?
  

I suggest you to refer to the below link where the same type of issue had been discussed, refer to the suggestion given by
Sharath Srinivasa on August 7, 2015.

Black screen after upgrading to Windows 10

Hope it helps, reply to us with the status of your issue. We will be happy to assist you.