Vista Guardian is a rogue anti-spyware program which usually spreads via trojan. This fake application installs to user’s computer without their knowledge. Once your PC is started the parasite starts its fraudulent scans.
As a result of those scans you will see fake warnings which malware floods on your computer’s desktop. This is all scam and you don’t need to pay attention to it. In this way Vista Guardian tries trick you into purchasing supposedly legal security tool. Malware hijacks your browser to the website which advertises “full” version of fake anti-spyware program. Instead of paying money for this fake security tool use decent anti-spyware tool and remove the parasite from your computer.