Xpy is a small free to use tool which lets you disable the default useless services running in xp and windows vista, it lets you tweak a large number of settings related to windows
The tool has been released for both windows xp as xpy and for windows vista it is vispa, with this small free tool you can do a great and high number of optimisations in windows
You can tweaks settings related to Services, Internet Explorer, Windows Media Player, Windows Messenger, Windows Desktop Search, Usability, Delete Files