RDilly is program that makes a backup copy of the NT,2K,XP registry. It's very similar to System Restore found in WinME and WinXP. You get a point-in-time copy of the registry labeled with the date it was made. You also are able to restore the registry to this point-in-time copy.

Windows NT,2K,XP or higher. For Vista, this program must be run as Administrator to function.

Freeware, of course!
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