False Anti-Virus Program

For over 12 months a false anti-virus scan and clean-up program has been popping up on my Internet Explorer and AOL mail account.  Conducts unrequested scan, of course locates many viruses and offers to clean them up for a "low" fee.  To compound the annoyance factor, it also provides a cul-de-sac menu of choices, all of which either require you to pay up or become frustrated stuck in a loop (unless you resort to task manager and close IE).  At first it was annoying; now after countless interruptions it's getting to me.  HOW CAN WE STOP THE MADNESS??? Can't Norton recognize and block this program?  Help!