Take a complete registry backup using ERUNT

ERUNT (The Emergency Recovery Utility for NT) helps you perform a complete Registry Backup and Restore in Windows NT/2000/2003/XP/Vista.
You can use this utility as a primary registry backup utility, apart from System Restore. ERUNT can be downloaded from Majorgeeks or from Lars' site.
Download ERUNT and install it. ERUNT sets up a shortcut in the Startup group, that backs up the registry for the current day, during the first Windows startup for the day. This feature is provided by Autoback.exe add-on for ERUNT. Learn more about this from the Readme page
To manually backup the entire registry using ERUNT, try this:
1. Click Start, Run and type the path to ERUNT.EXE

2. Click OK in the next dialog.

3. Put a checkmark near all the three items, and set the backup destination. Then, click OK.


Entire registry is backup up. Click OK in the resulting dialog.

The registry hives - Software, System, SAM, default, NTUSER.DAT (for the currently logged on user profile) are backed up to the chosen path. You can learn more on Registry Hives from Microsoft website