The windows registry--can't live with it, can't delete it. There are ways, though, to slim it down, give it a little polish, and give your system a little boost. Most of those ways are distressingly un-free, but Email Battles has a nice post about a trio of free tools that, in concert, will get the job done. First you use CCleaner to scrape out all the accumulated crap. Then you use RegSeeker to nuke the really hard-to-find junk. Finally, you use RegDefrag to physically defrag your registry to make it work faster. All three tools are free and together they'll make your registry feel like new.