Warning do not attempt to download "Personal Antivirus 2009".
My wife did it and its a nightmare, it pops up false security threats like trojans & worm infections and takes control of your browser (unless you pay them for subscription fees apparently).
No uninstall option, I had to manually remove it with Norton antivirus (which did not detect it!) and then it still had other little annoying programs running.
Finally got rid of it with "Malwarebytes' anti-malware" Free program.