We use both of these programs with Vista and XP. We highly recommend them.
You can try them at No Cost
Registry Smart  and Repair XP Pro 100% XP & Vista Compatible
(Great programs) The most comprehensive system repair tools on the market.
 

Backup your Address Book, the fast easy way.
Search for (*.wab) and copy them (2 wabs) to a floppy disk.
If you need to put them back,  just copy them back to the same folder.

* The hottest Registry cleaning software on the Net today!

* Repair XP Pro - (Great program) The most comprehensive system repair tool on the market.

* Scan your PC for errors absolutely Free (Very good)

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* Evidence Eliminator - Erase your surfing history total "privacy protection".

* Double the speed of your PC!Discover the secrets to speed up and optimize your PC in minutes!

* 100's of Very Good Assorted Free computer programs.