Taken from Maximum PC, January 2009 Edition

Captain Obvious says that the best way to prevent infection is to avoid viruses in the first place, but what he doesn’t tell you is how to do it.  And even though hackers continue to get more cunning in both delivery and execution, you can tip the odds considerably in your favor by practicing safe and sane computing.

If you receive an unknown or unexpected attachment, don’t open it no matter who it came from.  Not only are some viruses capable of emailing themselves to everyone they find in an infected user’s address book, but inexperienced computer users are just as guilty of passing along payloads as hackers are of distributing them.

Bit Torrent sites and peer-to-peer networking clients are also common modes of spreading infection.  When attempting to download a legitimate program – a Linux distribution, for instance – use the link provided at the vendor’s website.  Pirated software is a particularly popular source of malware, so if your moral compass doesn’t steer you toward the straight and narrow, the risk of infection should.

And finally, get in the habit of regularly checking for software updates.  New exploits are always being discovered in Windows, Quicktime, web browsers, and other common programs.