In the file monitor log after the installer starts to rollback i notice something is written to this file C windows\system32\config\software.log I think the files in here are used by the event log ...

"Starting Windows...Windows 2000 could not start because the following file is missing or corrupt: \\WINDOWS\\SYSTEM32\\CONFIG\\SYSTEM. "You can attempt to repair this file by starting Windows ...

Microsoft explains in a new support document that the missing registry backups everyone was thinking were caused by a bug are still available as part of Windows 10 system restore points and are ...