One of my favorite tech sites, Real Tech News, just put up a great post on windows XP tips. A couple of gems I want to remember:

• XP hides some system software you might want to remove, such as Windows Messenger, but you can make it show everything. Using Notepad or Edit, edit the text file /windows/inf/sysoc.inf, search for the word ‘hide’ and remove it. You can then go to the Add or Remove Programs in the Control Panel, select Add/Remove Windows Components and there will be the software and you can now uninstall it.
• Windows XP can be very insistent about you checking for auto updates, registering a Passport, using Windows Messenger and so on. After a while, the nagging goes away, but if you feel you might go insane before that point, run Regedit, go to HKEY_CURRENT_USER/Software/Microsoft/Windows/Current Version/Explorer/Advanced and create a DWORD value called EnableBalloonTips with a value of 0.
• The Start Menu can be leisurely when it decides to appear, but you can speed things along by changing the registry entry HKEY_CURRENT_USER/Control Panel/Desktop/MenuShowDelay from the default 400 to something a little snappier. Like 0.