Yesterday marked the end of support for Windows 98, Windows ME, and will be ending support for XP Service Pack 1 in October. I am not sure how many people are still running Windows 98 and there seemed to be very few Windows ME installations out there. I do know of a lot of people who have not wanted to go to XP Service Pack 2 just because they fear that the security enhancements will break something. In most cases it is an on-line game that doesn't play well with the default settings for the firewall. I am aware of one instance where XP SP2 broke a fairly common application. The default for FTP using IE in XP SP2 is to use passive FTP. In accessing one server we would get errors. It had mostly to deal with how the server firewall was set up but it worked fine with SP1. In the end it was as easy as unchecking the checkbox that said to use passive FTP and it works now. You can get more information at http://www.microsoft.com/windows/support/endofsupport.mspx.

Hopefully you have updated your systems to Service Pack 2. If not you have some time still. Get on it.