Do I need an antivirus program with Windows 7?

Episode 1147 (16:34)

Sam from San Diego, CA
Virus Alert

Sam bought a new Sony Vaio with Windows 7. What should he do about antivirus software? Leo suggests going with Microsoft Security Essentials. It comes bundled as Windows Defender in Windows 8, but he'll have to download and install it separately for Windows 7. Antivirus software won't protect him from his own behavior, though.

Sam is also wondering if he has to have a Windows password to log into his machine. Leo says if he is the only one who has physical access to the computer, then it's not necessary. He can disable that in the account management settings.