Windows 10: Can’t get past a sign in option error

so pretty much I have had a GPU blue screen error whenever I start up my PC sometimes it boot right up sometimes it goes blue screen but today and last night I tried to turn my computer off to avoid the blue screen and I restarted it and it said “ the sign in option is not available use a different sign in option or keep the device on for two hours” so like any reasonable person I tried to find a way to enter the password but I could not find one so I waited the two hours and then I got on and once I played for about an hour I logged off of it and then now I tried to get back on and it says th

:)

 

How to troubleshoot an error that appears only at Restart or Sign out?

I get an error pop-up error message not every, but almost every time I Restart or Sign out. It's the screen with blue background and on top of Restart or Sign out text an error window says:

Explorer.exe - Application error. The instruction at 0x000… referenced memory at 0x000... The memory could not be written.

Sometimes the error code is just zeros, sometimes random numbers. I have tried so much already to troubleshoot this. For example these did not help in any way:

• MemTest86+ (no problems)
• Disabling any Services, Autoruns/ShellExView entries
• Low resolution mode
• BIOS settings are fine, no overclocking etc.
• DISM.exe and sfc
• etc.

However, these do make the error go away:

• End process for explorer.exe before Restart or Sign out
• Safe Mode
• Creating a new user profile (almost the same as clean installing Windows, many full days of work)
• Uninstalling NVIDIA graphics driver (then the card is unusable, of course)
• Disabling Device Manager / Display Adapters / NVIDIA GeForce GTX 1080

I already contacted NVIDIA and the graphics driver is not the culprit. Something has gone wrong with the user profile as the same driver works just fine in a new profile (and there's nothing wrong with the driver anyway, it's just the Restart or Sign out process that has a problem).

What can I do to fix this? One useful thing would be to have a step-by-step procedure for the Sign out. So that it'd ask before continuing to the next step and list what it's doing. Or if I could just disable whatever it does when the error appears.

 

How does Windows boot to advanced recovery option e.g. command prompt?

- that gives me a 454 'Unexpected error' This tells me that the BCD is partially corrupted.

The commands: shutdown.exe /r /o /f /t 00
or: %SystemRoot%\System32\Cmd.exe /c reagentc /boottore&shutdown /r /f /t 00
should boot into Recovery if everything is configured correctly.
FYI, If Windows is configured correctly:

1. If Reagentc is disabled, you still can get into Recovery but with limited options.
2. If Reagentc is enabled, you'll get all options.
3. If you boot Windows using Recovery USB stick, You'll get into Recovery with couple of options missing.

Here's my suggestion if you want to try:
OPTION 1: Will save the trouble of re-install Windows.

1. Download the image of my first 3 partitions (450MB Recovery, 100 MB EFI partition, and 16MB unformatted primary)
   EFI_Boot-00-00.7z - Google Drive
2. Run Macrium and restore the image from step 1, overwriting your existing 1st three partitions, leaving C alone.
3. Delete the 490MB Recovery partition.
4. From Macrium, run fix boot problems.
5. Reboot. Open Admin command prompt then run Reagentc /info to make sure that it is enabled. If not, enable it.
   if failed to enable, reboot and try again.

OPTION 2: Assuming you've already had Windows backup with Macrium.

1. Wipe out the first 5 parttiions. (450MB, 100MB, 16MB, C Drive, 480MB)
2. Fresh install Windows 10
3. Restore C drive from backup image, run fix boot problems
4. repeat step 5 from OPTION 1 above.

 

Cannot sign in microsoft account.

My device: Lumia 520. GDR2.
I cannot sign in my Microsoft account on my device. It didnt say any error but Microsoft account is not listed in Email and account list. When I click add button, it will show microsoft account option but after press sign in, it is still not shown in email
and account. Another problem is i cannot delete facebook account. Error code: 0x83cf1202. I have tried as suggested here: http://support.microsoft.com/kb/2475837/en-us#step0x83cf1202 but as my Microsoft account is not shown, I cannot do step 6.

Any suggestion?