The best free Registry Cleaner is
Comodo Registry Cleaner
http://download.cnet.com/Comodo-Registry-Cleaner/3000-2094_4-10895685.html

http://www.warp2search.net/contentteller/news_story/comodo_registry_cleaner_review.html

http://www.ccleaner.com/

This is better’ Glary Utility’s.

http://download.cnet.com/Glary-Utilities/3000-2094_4-10508531.html

This download has the ask tool bar as a option. Un-check the ask tool bar box and it will not include it in the download

Most people will tell you to use the free cleaner "CCleaner" which u can get from http://www.ccleaner.com – but this is BAD because it just tries to find as many problems as possible to make itself look good (why else would it be free)?

You need to be careful with the regsitry because it’s a crucial part of your system. If you screw up one of the important files inside it, you’re going to have BIG problems down the line… so you need to be sure the registry cleaner you use will be as "delicate" as possible with your PC.

The best regsitry cleaner I’ve used is one called "RegCure". It’s very fast at scanning and it speeds up your computer a lot. You can see exactly what it does here: http://www.fastregistryfixes.com/regcure_review.html