Aside from the active malware scanner in windows and a firewall, Not much else is needed until after the fact (everyone gets pwned eventually, that's when these tools come into practice). Good common sense opsec will save you a headache. Or as others suggested, ditch windows entirely, Not that Linux is 100% safe either. At the end of the day, most security breaches don't happen because of the computer or os, they happen to the component sitting between the chair and the keyboard, IE you. Don't be retarded and you won't get malware.
