I found the freeware Registry Cleaner that I was looking for. You should add it to your list, it's a good one: RegScrubXP and it's available from here: http://www.lexundesigns.com/LexunFreeware/
You guys should post some of the hardware diagnostic tools that boot from CD. Some of them are free including Memtest86+ and DFT (Drive Fitness Test made by Hitachi). Both are excellent testers to find if you have a bad HDD or memory. Check the links here:
now its a pain to view all the pages and decide what to download.. Please update the list at first page.. and put the utilities that are worth of download from all the replies.. hope its gonna be soon now.
This is a very good site. Not anything overly great, but good never the less.
I don't know if it has been mentioned but Major Geeks has free programs that they certify as being spyware free. There are some great system tools there.