What the hell did you do with Win7?
I've had 0 problems OS related, and that's a lot coming from a computer so strained by higher graphic games and other stuff.
My preamps won't work with it anymore, my phones aren't recognized when I plug them in, my browsers are crashing constantly, explorer.exe keeps freezing and having to restart, ALT+TAB results in the game crashing, sound card buffer keeps failing while I'm recording music, Flash (in browser) keeps crashing, everything feels incredibly slower (copying/moving large files, starting up programs, games, etc.).
I don't have any viruses, I've defragged, I've done a chkdisk, I've reinstalled all my drivers, I've checked for driver updates, I've reinstalled programs, 7 just seems to be failing on me or something.