Need help with blue screen error.

1

Try a system restore using this method, that will undo any changes you made in the registry.

Start your PC, just as Windows attempts to load (spinning dots), press and hold Power Button for 5 - 10 seconds to perform a Hard Shut Down

Do this twice

On the third start Windows will boot into the Recovery Environment and from there you can access System Repair, Safe Mode, Command Prompt... etc.

Go to Troubleshoot - Advanced Option - System Restore

Check to see if you have a restore point you can go back to.

2

If the System Restore option is unavailable or does not resolve the problem, you indicate you have data on the D drive, that drive would be unaffected by performing a Windows reset, do you also have data on the C drive that is not backed up that you need to keep.

A deleted or corrupted registry entry can cause repeated blue screen errors and prevent normal startup. If Windows no longer boots normally, recovery options must be used; these can usually preserve data on non‑system partitions such as D:.

Use these steps in order of least to most disruptive:

1. Try System Restore from Windows Recovery Environment (WinRE)
   • Power on the PC and interrupt startup (hold the power button to turn off) 2–3 times until the Choose an option/recovery screen appears, or use installation media to reach Repair your computer.
   • Go to Troubleshoot > Advanced options > System Restore.
   • Select a restore point from before the registry was changed and complete the restore.
   • System Restore targets system files and registry; personal data on D: should not be affected.
   If BitLocker is enabled and a recovery key is requested, retrieve it as described in the CrowdStrike KB (using https://aka.ms/aadrecoverykey from another device) and then proceed with System Restore.
2. If System Restore is not available or fails, try Safe Mode
   • From WinRE: Troubleshoot > Advanced options > Startup Settings > Restart.
   • Press the key for Safe Mode.
   • If Safe Mode starts, back up important data from all drives (including D:) to external storage.
   • After backup, consider using Reset this PC (see step 4).
3. Check for registry‑related bug checks
   • If the blue screen stop code is REGISTRY_ERROR (0x00000051) or BAD_SYSTEM_CONFIG_INFO (0x74), this indicates severe registry or configuration damage.
   • For REGISTRY_ERROR, the guidance is to analyze with a debugger; for non‑developers, the practical path is to use System Restore or recovery options.
4. Use “Reset this PC” while keeping files
   • From WinRE: Troubleshoot > Reset this PC.
   • Choose Keep my files. This keeps personal files on the system drive (usually C:) while reinstalling Windows and removing apps/settings.
   • This process does not normally touch a separate D: data partition, but critical files on D: should be backed up first if possible.
5. If reset fails, use installation media but avoid formatting D:
   • Boot from Windows 11 installation media.
   • Choose Repair your computer first and retry System Restore or Startup Repair.
   • If a full reinstall is required, use Custom install and delete/format only the system partition (typically C:), leaving D: intact. This preserves data on D:, but again, backing up D: beforehand is strongly recommended.

If the registry damage is extensive and System Restore/reset cannot complete, the only reliable fix is a clean Windows installation, taking care not to format the D: partition and backing up data before any risky operation.

References:

• Bug Check 0x51: REGISTRY_ERROR
• Bug Check 0x74: BAD_SYSTEM_CONFIG_INFO
• KB5042421: CrowdStrike issue impacting Windows endpoints causing an 0x50 or 0x7E error message on a blue screen