How To Make Windows XP Run Faster.
 

I have this theory that sludge builds up inside a computer over time, much
like an automobile engine. After a while, it doesn't start right up like
when it was new, it stalls unexpectedly, and performance is sluggish on the
(information) highway. Is there something like engine cleaner we can pour
into our personal computer to restore that "like new" performance? Actually,
yes!

Direct link: http://www.thetechzone.com/?m=show&id=327

Image your O/S partition after fresh install with all updates; 6 months later after you get tired of the games, restore the image as if you have a new PC. :)