When you load Windows Vista you get a blue screen with the following error:

“Stop: c000021a {Fatal System Error}
 The initial session process or system process terminated unexpectedly with a status of 0×000000000 (some more hex codes)”

Also System Restore through Repair Environment which did not work either, it kept saying unexpected error or something like that.

What I tried

• Clean install of Vista
• moved contents of system32\config from broken install to clean one
• also moved old Users directory

Problem still exhibited. Must be a registry/configuration issue then, not system files.

Cause

The problem was within the SOFTWARE hive. To verify I moved all the clean install stuff (Windows , Program Files, Users, ProgramData) to a folder called “clean” and moved all the folders out of Windows.old back into C:\ , so in effect returning the machine back to its original state before the clean install. I then replaced SOFTWARE with SOFTWARE.OLD and all is well.

Solution

• Boot into the recovery enviroment
• Navigate to c:\windows\system32\config
• rename SOFTWARE to SOFTWARE.off
• navigate to c:\windows\system32\config\RegBack
• copy the latest SOFTWARE file to c:\windows\system32\config
• reboot computer

Windows should now load ok but you need to do a few thigns for completeness.

• create a new system restore point
• run system restore to a suitable point. This makes sure all of the registry and files all match up
• reboot the computer

Done