Complete the following steps to attempt restoration from a non corrupt registry.
- POWER OFF your PC immediately.
- Boot to external media of some sort (NOT your Windows installation) and navigate to the %SYSTEMROOT%\system32\config folder.
- Backup the registry hives in this folder to a temporary location. The files are:
- SOFTWARE
- SYSTEM
- SAM
- SECURITY
- DEFAULT
- Navigate to %SYSTEMROOT%\system32\config\RegBack as mentioned earlier.
- Copy all registry hives from this folder (the same files as listed above) into the %SYSTEMROOT%\system32\config folder.
- Reboot the PC.