[notatoad]

stop. don't use an antivirus. back up your data, and use a tool like acronis to take an image of your system state. If you get a virus, re-image.

if you keep your OS and browser up to date, and don't open random sketchy EXEs, you'll be fine.

[pyr0m4n]

Without AV, you could be infected for months without ever knowing... :) so unless it's some stupid malware, what would trigger you to reimage?

[AnthonyMouse]

With AV you could be infected for months without ever knowing. All it takes is to get infected by anything that hasn't made it into the (often out of date anyway) definitions.

The old school Unix method works very well: Keep a list of all changes made from the base install, then periodically swap the disk out for a blank one, follow your documentation and restore non-executable user data from backup. Also has the benefit of regularly validating your documentation and testing your backups, and allows easy rollback by following the same process for major OS updates or hardware upgrades.