I use Windows 7 (among other O/S's)
I'm using Arduino 2.1.1 and in light of the recent update for 2.2.1 and having heard that it won't run on Win 7 and the comment of @gfvalvo using Eclipse and how he found that information in approx 60 seconds
so, i decided to "Use the Force"
and move to another IDE, Truth be told i have not ever used another IDE so... Why not?
This thread will explore different IDE's
Pro's and Con's