This is a real pain.. while surfing for content on a Security class XP Antivirus installed itself. If continuously nags to say you have virus's (which are false) and asks for money. It has a believable interface and looks like an actual Microsoft program.
To remove http://www.myantispyware.com/2010/11/11/how-to-remove-xp-antispyware-2011-virus/
This needs you to create a registry patch file, then we ran
Which finally removed the damn thing!