Jesus are you guys serious? I've run both windows and osx for years, and in the past 15 years I've only had a virus twice on windows. One was Noint, in 1994. It's about the most harmless virus ever, and the other was totally my fault, I won't get into details, but safe browsing and good antivirus will keep viruses away.
What are you guys doing that you keep getting viruses?
Honestly, you have a very ignorant attitude about the realities of the internet today.
Viruses compose a VERY, VERY small threat today, the real threat is trojans.
Facebook, Myspace, Yahoo, and many other legitimate sites have been known to hand these out on accident. Energizer batteries USB charger was just found to be shipping with a trojan.
Worse though, is that Mac users think they are impervious. Sorry, but there are quite a few trojans for them as well. Not even Linux is safe. If you are on the internet, you need protection.
Most people don't know they have trojans, adware or even a virus because their head is stuck in the sand and never check. How do you know you have nothing if you have no way of knowing? Not every one of them will bring your system to it's knees. The VERY best anti-virus can't do more than about 80% of what is in the wild. Protection is all re-active, not pro-active. It will take less than a few minutes for the next huge virus to spread world wide, if your anti-virus updates once per day, you do the math.
If your Windows system has been online more than 6 months, I can pretty much GUARANTEE you I can find something on it (trojan, virus, or adware, most likely adware AND a few trojans). That is, unless you have some seriously robust protection and a good head about what is safe and what isn't, and no Norton Internet Suite isn't that robust. 3 months if you have kids. 1 day if you are a bitchy office manager who thinks she can do anything she wants on a company computer safely. Unless you work in the industry, the odds of you knowing what is and isn't safe and what is a truly robust protection
system (not suite) are pretty slim.