Windows Critical Process Error and Login Password Issue (Win10)

[breezyintrepid]

After upgrading my motherboard from an MSI B450M to a Gigabyte B550M DS3H, my system initially worked fine. However, after adjusting BIOS settings to unlock an HDD SATA port, my computer encountered a BSOD with an "inaccessible boot device" error, despite booting from my SSD without prior issues.
Upon reboot, I reached the account selection screen where I entered my password successfully. I then restored to a previous restore point, requiring reinstalling Gigabyte apps which led to further issues. Subsequent reboots resulted in a "Critical Process Died" BSOD, returning me to the account selection screen where my password suddenly became invalid. Despite knowing it was correct (as I could use it on other devices), attempts to log in repeatedly failed.
Efforts to access advanced startup options, command prompt, or recovery tools were unsuccessful, as each attempt led to another BSOD with the same error. Even after changing my password and trying an app password, the issue persisted.
Pressing the "Forgot your password or don't see your account?" button only resulted in a cycle of reboots and BSODs without accessing any administrator accounts or resolving the issue.

I urgently need assistance as I'm unable to use my PC.

 

[markwilson]

If you're facing a Windows Critical Process Error and Login Password Issue in Windows 10, try these steps:

Fix Critical Process Error​

1. Boot into Safe Mode
   • Hold Shift while clicking Restart → Troubleshoot → Advanced Options → Startup Settings → Enable Safe Mode.
2. Run SFC & DISM Scans
   • Open Command Prompt (Admin) and run: sfc /scannow
     DISM /Online /Cleanup-Image /RestoreHealth
     
3. Update Drivers
   • In Device Manager, update outdated drivers (especially graphics and chipset).
4. Check for Windows Updates
   • Win + I → Update & Security → Check for updates.
5. Perform System Restore (if available)
   • Boot into Advanced Startup → Troubleshoot → Advanced Options → System Restore.

Fix Login Password Issue​

1. Use On-Screen Keyboard
   • Click Ease of Access on the login screen → Use the on-screen keyboard to enter the password.
2. Check Keyboard Layout
   • On the login screen, check the input method (bottom-right corner) to ensure correct language settings.
3. Reset Password via Safe Mode
   • Boot into Safe Mode with Command Prompt and enter: net user YourUsername NewPassword
     
4. Use Password Reset Disk (if created earlier).
5. Reset Windows if nothing works
   • Win + I → Update & Security → Recovery → Reset this PC.

Need more details on any step?