After installation of KB4056892 boot failure, after roll-back error 0x800f0845

 an easy way to kill explorer.exe with Narrator's help

Get into Administrator: Windows PowerShell and type and Enter this:

(Get-Process explorer).Id |% {cmd /c taskkill /PID $_ /F}

The taskkill /F switch works where PowerShell's Stop-Process -Force does not.  Thanks for making me find this.

Then note the difference.  All explorer generated stuff is removed from the display and stays removed.  More significantly Alt-Tab now shows only icons.  Surprisingly some modern app windows are still functional!  Who knew?  To get explorer restarted just do it conventionally (e.g. with Task Manager) or in PowerShell  Start-Process  explorer   works.

Good luck

Robert

EDIT: Tried low resolution mode and seems to be the same result (only larger mouse pointer in low-res). I'm going to try letting it run a bit as described below to see if anything different happens.

Could there be a third display involved?  I have seen this before--windows get left on a screen that is no longer detected but was once primary and it stays primary until I switch it.   The problem with that scenario for explaining your case is that you can see the Project dialog and that means you are on the primary screen.  Also, with Low res I don't think you are allowed to have multiple screens.  In any case try pressing  Win+Shift+CursorRight  to "throw" a window over, especially if Narrator has identified it for you after pressing Alt-Tab.  Note that Alt-Tab lists all our windows regardless of their states, so it is a more complete list than Win-Tab but it is a less functional display than Win-Tab.  Also, when explorer.exe is stopped Alt-Tab can still be used but then it shows only the task icons and navigation is only available via Alt-Tab and Alt-Shift-Tab.  I think if we could figure out an easy way to kill explorer.exe with Narrator's help you might be able to start seeing something.  Unfortunately usually killing explorer.exe means that it is just restarted again.   Task Manager can do it but that might be too complex a task to try to do blindly even with Narrator's help.

tried to use its Tools menu but got taken to ms-settings:magnifier (or whatever it is--nothing obvious like that) which of course for you would require a completely functional explorer.exe.  

Found this (obscure syntax):   ms-settings:easeofaccess-magnifier

Actually I almost had that but used a slash instead of a dash for a subtopic separator.   Good to know.  Guess they are giving up on the pretense of calling these things URI (which IMO would require the // following the colon at least--otherwise it just parses like a relative drive specification).

If you want to try starting that without using the Magnifier window's Tools button you could use the following syntax from Task Manager's File New,  Command Prompt's or PowerShell's command lines:

explorer.exe  ms-settings:easeofaccess-magnifier

However, since it is now looking that your problem is going to involve the fully functional availability of explorer.exe that may not accomplish its normal function in your current state.

FYI

Robert

 who knows at this point.

Please use Narrator to keep control even though you can't see what is going on anywhere.   I'm mystified about that.  I was hoping you would be able to see more with Low res.  Note that as soon as any Accessibility program is running you would have something to show in an Alt-Tab list.  So, it is surprising that you can't see either Task Manager or Narrator on the screen.   We can ignore the state of explorer.exe in that case (or then learn to start focusing on its problems and try to figure out how to work around them).

Another one that would change the video to be viewed is Mangifier in its Fullscreen mode with its Reversed video option.  OMG.  They have "modernized" that too?  I  just got Magnifier started conventionally with Win++, got into its Views menu and switched to FullScreen, and then tried to use its Tools menu but got taken to ms-settings:magnifier (or whatever it is--nothing obvious like that) which of course for you would require a completely functional explorer.exe.  

<voice actor="Dorothy" >  Toto, this isn't Kansas, is it?  </voice>

Have you tried starting Narrator to help with workarounds?   Win+Ctrl+Enter.  Do you have a second monitor to attach?   It sounds like your video driver is a problem.  You could use the Login screen's Power button's Shift-Restart command to get into the Advanced Boot Options to try using Low video resolution with a retry.  This would be an even simpler option if you had a boot menu to start from.

Good luck

Robert Aldwinckle

---

Thanks for the reply and suggestions. I tried connecting a 2nd monitor and can switch between them using Win+P (very strange). As mentioned, I've since removed the video card and am only using on-board video at this point to hopefully simplify matters/drivers. I will try the low resolution option to see if that gets any better results.

EDIT: Tried low resolution mode and seems to be the same result (only larger mouse pointer in low-res). I'm going to try letting it run a bit as described below to see if anything different happens.

On a related note, since it "appears" to be booting into the respective user account (albeit a black screen), if I leave my LAN connected, and leave the PC for awhile, is there a chance it will run Win Updates in the background and the issue might self-correct? Wishful thinking I know, but who knows at this point.