Proper setup for virus protection varies wildly with different operating systems, machine users, security requirements, and personal preference.
1) Use common sense
Most problems associated with viruses and malware can be avoided by simply using some common sense. Don’t download attachments from unknown parties and run them! When possible use open source software so there is nothing hidden. Don’t leave your machine on when there is no reason to. Back up everything important! Storage space is cheap, and even if you have avoided malware your hard drive could still crash.
2) Don’t overreact
Computer viruses and malware are a threat to almost all computer users, but quite often computer users overreact to this threat and and as a result suffer more negative affects such as down time, software problems, and spam. Fake or out of date forwarded virus and worm warnings continue to circulate around the internet, acting like worms themselves. Keep in mind that some malware pretends to be antivirus software!
3) Maintain a security policy
Anti-virus and anti-malware decisions will be easier to make if a security policy is in place. Does your machine have any data on it that if leaked would pose a security risk? Does your machine function in a mission critical process such as a single server? If the answer to these questions is yes, you should keep a strict security policy – for example perhaps avoiding internet browsing entirely on these machines, and maintaining top of the line security and anti-virus software. If there is no top-secret data on your computer, and if a crash will not mean the end of the world, you will be better off with a relaxed security policy.