1. The registry is backed up daily for the last five days in Win9x (default set in the BackupDirectory key, SCANREG.INI).
2. The compressed x.CAB files (rb00x.cab, where "x" can be 0 to 5) are stored in the \SYSBCKUP folder by default. When the computer is booted each new day, the next number is created and after the default number (5) is reached, the older file is replaced.
Caveat: Setting the "Backup=" line to 0 (zero) in the SCANREG.INI file will circumvent Windows 98 from backing up the Registry totally. However, if the Registry isn't being backed up and this is not the cause, please read the Microsoft Knowledge Base article, subject "Registry Is Not Backed Up Automatically at Startup (Q198864)."
3. If the box labeled "ScanRegistry" is disabled in the "Startup" tab menu (System Configuration Utility (MSCONFIG)), the system registry will not be backed-up during boot.
4. From the MS-DOS prompt any of the backups can be restored, [Q184023]. Boot to the command prompt and type Scanreg /restore and then press enter. Follow the directions to select which backup you want based on date saved.
5. To perform a manual backup after a computer has booted, simply type scanreg on the Run line, and then press Enter.