Jim Allchin (and others) are now saying no antivirus program should be used in Windows, especially windows vista. They have a good point, if the security of the OS is really up to snuff, and if you're not an idiot, then you should be fine. But...sometimes viral payloads get delivered without user intervention. That being said, i recently liberated our house from Symantec, having gotten tired of it it's lack of support for Win64, and the general slower-than-molasses feeling. I upgraded to Kaspersky internet security for J's desktop, it's a great AV program and not CPU intensive. For my Win64 system, I rely on NOD32/64, one of the very few programs that will actually run in Win64. It's a great program and very low maintenance (and at least currently totally free). In fact i haven't touched it since i installed it, and it grabs and installs anti-viral updates ever day.

Now, when I upgrade, I won't touch Symantec with a ten foot pole. I'll get Nod32 or Kaspersky or a similiar program.