Seriously, try
http://www.blackviper.com/
I have always been a cheapskate and been behind the technology curve when it comes to having the fastest processor or graphics card. But with the help of Charles Sparks and his site, I have been able to squeeze everything possible out of a machine. When most were running Hoster 3.xx on a dual core pentium, I was running on a 700Mhz Duron processor.
Just spend a little time reading through the site and making all the changes. Nothing you do in the way of disabling services is permanent. Anything you turn off can be turned back on. I run the bare-bones setup on my show machine with the exception of a couple of items. My recommendation is to start with the "Safe" column and work from there. I would wager that just turning off the items in the "Safe" column will alleviate your issues.