Yes, I suffered many year with virus in Windows XP, to the point of having one computer for internet (with linux, debian), and my development computer (which I used to work in 3D Animations for TV Commercial) never connected to the internet.
Now, with Windows 7, I don’t have problem with virus, I can say that I even forget about viruses. I use Norton Internet Security for almost 7 years (I purchase anual license), and trully NEVER had problems with viruses once again.
I also don’t download too much stuff, and only navigate on “safe” websites.
The only problem with Norton is that many times it deletes files, like small programs I download, plugins for sotwares, even zipped files, which it “considers” as virus. But this is easy to fix, just setting up folders for exclusion from scanning, and you can always go to quarantine and restore these deleted items, and tell norton to never remove them again.
Cheers!