this site is very helpfull ...... help u to make ur pc faster .... hope this site help u a lot http://www.tweakxp.com/userinterface_tweaks.aspx
well tweaking is ok since windows is very raw but if someone that is n00b to pcs that could be troublesome... and f*ck windows up with just a simple mistype and stuff like that.. probably it would be better to get some automatic tweakers like tuneup utilities etc