I received these from a Vendor and thought they may be of interest to some.

PC Pitstop has free computer checkup and diagnostics that can help you detect and fix many common PC problems.

PurePerformance has lots and lots of tips for almost every Windows O/S.

Paul Thurrott’s Super Site for Windows is a Windows & .Net Magazine sponsored site with loads of info.

Dynamic Zone FX has a series of "workshops" complete with the screen captures to help you through.

Free PCTech has a huge list of tips and explanations in order for you to get the most out of XP.

Bob Cerelli’s Windows site has categories of tips including performance, internet and repair.

MVPS.org has Windows XP registry fixes, utilities, illustrations and tweaks.Note:
I have no direct interest, profit, nor gain in these sites :). I just wanted to share what hopefully are some added resourses to your arsenal.