I'll just point out that the problem in using a Win2K system (or any older OS) on the 'net is not so much to the user (though obviously theres a big risk there) but that these old operating systems are easily compromised and added to botnets -often as control nodes
The inherent lack of decent security policies in these old machines make them easy targets. You often find an old Win2K server sitting in the back of a room, acting as a mailserver or webserver with no maintenance done on it for years. They're easy to hack, easy to control - and its a case of "out of sight, out of mind" - once compromised they can be there for years churning out spam - or worse