Freeware registry backup.

ERUNT is a freeware tool for backing up your registry in Windows XP or Vista. Older versions of Windows automatically backed up the registry, but when Windows NT came along, the automatic backups ceased. This where ERUNT comes in, making it easy to back up your registry to another folder. As an added bonus, you also get NTREGOPT, an optimizer that compacts your registry and eliminates fragments that would otherwise slow down access. Two great programs for the price of one!