The answer is MS do it because they know they can get away with it, there's not much in the way of an alternative to Windows these days, all those unixy type systems are still too fiddly to be attractive to joe public, XP & 2k are so simple to use that even the people who should never be allowed near a computer can use them, shame about the bugs, put them down to user error or your system isn't up to it ;)