Anybody ever noticed that all Microsoft OS disks are not copy protected? From the days of DOS, to the Windows 3.1 floppies, all the way up the Windows XP CD ROM. I wonder if it was so that when asked, Joe public would say Microsoft DOS or Windows rather than some competing OS. There were a few around at the time, I remember C/PM and DrDOS.
Basically, rather that try and prevent piracy and pump millions of dollars into protection systems, I think MS have accepted the fact that the pirates will crack ANYTHING eventually, and have simply used a bad thing (piracy) for their own ends (getting a Microsoft product onto virtually every PC in the World). Now that's business genius and a reason why Bill Gates is the richest bloke in the World (or as near as makes no odds).