1. The article [Q183887] explains that when a computer is started successfully, the Windows Registry Checker tool (Scanreg.exe) creates a backup of system files and registry configuration information (including user account information, protocol bindings, software program settings, and user preferences) once daily. Files backed up include, System.dat, User.dat, System.ini, and Win.ini. To use this tool with the /restore parameter, the tool must be run from a command prompt (booted to) outside of Windows where one of up to five registry backup files may be chosen from the list to restore.

2. Review the article [Q184023] for the many Command-line Switch options which may be used with the Registry Checker tool.