Trend PCcillin has identified spyware/adware SPYW_NETZANY.100 on my desktop, which runs XP with IE6. (Lavasoft Ad Aware and Microsoft's antispyware beta do not detect it.)
But after I remove the file with PCcillin, Internet Explorer either refuses to open at all, or gives me the message that it has 'encountered a problem and needs to close'. I recover through System Restore, which restores IE functions but only in company with the NETZANY file. The spyware gives no tangible performance problems, but I'm not happy having it live on my pc.