There is a lot of duplicate programming on most PCs and Vista is loaded with unused prgs we don't need in a DJ & KJ show, turning off all sorts of processes like auto updates.
Delete all extras like log on sounds I don't need a sound for the recycle bin, low battery yes, ect in the media sample music, pics, who needs more than one arrow pointer? Every little bit helps. My Vista PCs came with the 2007 extras good for students but alas. Had a BigFix prg. 13 different ways to get on the internet, several toolbars for that. Napster trash ect. Most of our PCs will benifit from a good cleaning. Do a search on your C: for .jpg hoo boy do ya really need all that. I'm trying to help, mine went up a notch or two.
This will help some plus you can check the ram %
http://www.speeditupfree.com/