(B) For all the junk and misinformation out there, it's actually pathetically easy to keep viruses off a PC:
- Install Firefox and Adblock Plus. Never use IE... EVER.
- Keep your system patched with MS update (the only use for IE)
- Install Antivir, Spybot S&D, Spyware Blaster and keep them up to date
- No P2P software, no torrents (unless they are trusted ie from Pirate Bay)
- No software/gaming cracks unless they already come in a trusted torrent
- If you're really paranoid, run your windows apps in Sandboxie
Problem solved. Where most people screw up is they run IE and don't keep their system patched. If you're running IE, you're basically asking for someone to crash your system.