I would agree totally with CodeDog in that your best bet with Win7 is to use Microsoft Security Essentials as your AV choice. It works, and it works incredibly well. It was designed for your OS. I don't think about viruses any more--other than to always keep both eyes wide open ALL THE TIME. Bad websites will get you as always, but if you consider yourself a programmer you probably (must or definitely should) know this already. Regarding MSE, you won't even know it's there. No other AV can say that. And I would also say (you are an adult, so don't cry later) you should dump that AV you're using now and get MSE as fast as you can. Heck, it's free and your computer will thank you.
I love the guys on this forum, and they will always help you in ways you've never imagined, but many of them have long, lesson-learned, hard-boiled techniques for avoiding viruses. It is impossible to put their methods into a neat package. They most likely will not all have Win7. Consider that. Assembly programmers are an eclectic bunch and there is no doubt that while we may each disagree on literally everything--we all do play on the same team.
So, dump the AV, redo MASM, seek out jj2007 with his MasmBASIC and start banging some keys. And finally... good luck. This is a good place.