all of us get fed up with windows at some time or another, so here's a substitute called reactOS. it's based off of 2003/XP windows, though that means it might be kicked right back over if windows 7 gets its foot in the door for programmers.
the big thing being that it also supports COlinux natively (bottom of the reactOS homepage)
http://www.reactos.org/en/index.html

