I've had a few viruses in the past: Ironically, I got them Microsoft's own install media...
- A computer I got back in 1995 came with a bundled set of MS-DOS 6.22 and win3.1 disks. The shrink wrapped MS-DOS 6.22 had a boot virus on disk 1, which I would incidently keep getting upon a fresh format/clean install. The disk came shrink wrapped, with all the official Microsoft EULA docs and everything included, not sure what was up with that...
I had various AV on my comp then, and it never seemed to get detected, until something (don't remember what anymore) detected it back in 1998. A scan of the disk showed the disk came infected (and the disk would't have got it from the PC, as I always kept the floppies write protected so there couldn't be any accidental deletions or what not...)
- Dont think my comp ever got it, but win 3.1 disk 5 had another virus on it, also came shring wrapped, yadda, yadda...
- A few years ago a format/fresh install resulted in my comp getting plasted by one of them worms, within a second of putting my IP info in, so I could go to Windows Update for the fixes for the dratted thing. Before I formatted, I was fine (when it was more prevalent) as I already was fully patched, had a firewall setup, etc...
I currently use McCaffee (had since Norton started that product activation, which I sort of do not prefer), along with Spy Bot and AdAware (for malware), though if something better has come along, I wouldn't be unamenable to giving some other product a look see...