[Lackatee]

A lot of those guides are kinda out dated, but theres still some goodies in there you can use. Heres some i have bookmarked.

Aviel Segal music AND his Computer audio performance, Windows XP tweaks & DAW optimization guide. - Probably the best one
XP Performance Tweaks
Music computers optimisation and Windows XP tweaks from Phil Rees
Optimize XP
Optimizing Windows 2000 and Windows XP for Audio
http://www.tascamgiga.com/pdf/optimizing-xp-and-2k.pdf