Nothing bad happens to me on Windows.Well, not on my computer at least. Back when I was sharing the family computer (an old Windows XP), it was riddled with bugs and viruses and spyware and other not-nicities. I blame Windows users, not the OS, for all the bad stuff happenening because they don't have a clue what the heck they're doing half/most/all the time.
My computer hasn't had one problem since I got it in November. *lose* I've never reinstalled my OS, either, though it would probably do wonders for the crap family computer.