I was getting an error when I tried to open iTunes that said "iTunes has stopped working" and it asked me if I wanted to send the problem to Microsoft. The error appeared after about a minute after clicking to try to open it.
I am running Windows 7, and have never before had a problem with iTunes. The only thing I have tried is reinstalling iTunes - I just downloaded the latest version and installed it (didn't delete the old one first). The result is that now I don't even get an error message, just nothing, when I try to open iTunes.