Anti-Virus
Anti-virus software is a critical part of protecting your computer from worms, trojans, and viruses that traverse the Internet. For any anti-virus software to be effective, it must be updated on a weekly basis, if not more often.
There are several software developers for anti-virus. The three most common are Norton, McAfee, and Grisoft. Norton includes 12 months of virus definition downloads with the purchase. AVG Anti-virus (by Grisoft) is free for both the program and virus definition updates. Grisoft also offers a paid version of their anti-virus that includes additional features.