In case you haven’t read about it elsewhere, there’s a serious security problem which affects just about ALL Windows machines going right back to version 3.
http://www.drkeyboard.net/viewtopic.php?t=3068 for more information and links to (temporary) fixes.
This one is VERY serious, you need to do something about it right now. Exploits are already out in the wild and you really can get infected this time just by viewing a picture in a web browser.