My suggestions:
1) You should have a firewall, any firewall, as long as it works, here are some popular ones:
Zone Alarm:
http://www.zonelabs.com/store/content/comp...kulist_downloadSVGate:
http://dl23.sygatetech.com/pub/bws/bws_49/spf.exeMore at:
http://www.snapfiles.com/freeware/security/fwfirewall.html2) You should scan for adware using every program available, first I would suggest an online scan at Pest Patrol: (click the scan now button)
http://www.ca.com/products/pestpatrol/Spysweeper (30 day trial for updates) (the best anti-spyware program I have found, too bad it is shareware):
http://www.webroot.com/products/spysweeper/Go here for more anti-spyware tools:
http://www.snapfiles.com/freeware/security/fwantispy.htmlGood site for general info on Spyware:
http://www.spywarewarrior.com/rogue_anti-spyware.htmPop-up blocker (may help with IE pop-ups):
http://www.kolumbus.fi/eero.muhonen/FS/Downloadfsc.htm3) Check the start up list for potential spyware like Mischabob suggests, and also running processes using x-ray my pc:
http://www.x-raypc.com/download.htmland, finally use toolbar cop to check for bad explorer plug-ins:
http://windowsxp.mvps.org/toolbarcop.htm4) As a last resort uninstall programs that you do not need and that may have installed the spyware, like file-sharing programs (Kazza,Morpheus) and "free" games which contain tons of spyware as I found out the hard way

5) Re-install Windows only if absolutely necessary (very last resort)
Spyware is evil, curse all who produce it, MUHAHAHAHAHHAHAHAAAA !!!!