We switched to the MAC OS two years ago due to all the virus and spyware issues. The MAC OS isn't a target, so it has been great. I find that the MACs also seem to have better graphics and they seem to run faster than the numbers would suggest (except for gaming). You can run Windows applications on Virtual PC, but they are a bit slower (not enough to be a bother for me). My daughter stuck with Windows and is running XP Pro. She has been attcked by spyware twice in the last three months and has to reload the OS after. A pain in the rear IMHO.