It is for XP only: there are a few steps that could easily be deleted for Vista, but I cannot test it.

Obviously use is at the users risk: I strongly advise reading the script to assure yourself that you agree with what it does. Some of is is obvious and uses the official MS command line tools. Some of it manipulates the registry in ways of varying obviousness.

Since the registry is notorious for its poor documentation I might be wrong is what some of the more arcane setting do.

Havind said that I have run it on several machines and never seen a problem.

Here is the script source: as html xp_tuneup.bat.html

and as a zipped batch file xp_tuneup.bat (zipped)