McAfee AntiVirus Plus 2010 (1-User) for free after a $30 rebate. Here is a screenshot for your reference. Note that the rebate is in the form of a prepaid Visa card, and it is NOT necessary to own the previous version of the software to qualify for the rebate. This program shields PCs from viruses, spyware, and has a firewall, and more. Most places have it for about $19.