Can't login after choosing "Diagnostic startup" in msconfig?

Solution 1:

OK To fix this specific issue, I had to do the following:

1. Hold Shift and click the power icon, choose "Restart" and wait until you see the blue Windows recovery screen.
2. Choose "Advanced" and choose Command Prompt
3. You'll restart and you should be put to a screen where it asks you for your MS Password. Input that and you should get a Command Prompt.
4. Input the following commands:
5. move c:\windows\system32\utilman.exe c:\
6. copy c:\windows\system32\cmd.exe c:\windows\system32\utilman.exe
7. Restart your computer.
8. On the login screen, now click the "Ease of Use" icon at the bottom-right next to the Power button.
9. A command prompt will open.
10. Type "msconfig"
11. Change the "Startup Selection" to "Normal Startup"
12. Restart the computer.

From there you should be able to log in with your PIN as usual. The last step is to clean-up what you did and re-enable accessibility:

1. Open a folder explorer and go to C:\
2. Copy the "Utilman.exe" file from there into the C:\Windows\System32\ folder
3. It'll ask for administrator privileges, Continue, and you should be back to normal.