BleepingComputer.com: Antivirus that won't slow computer drastically??

Anybody have a suggestion for a simple and hopefully free virus protection that doesn't kill desktop performance? I recently bought Norton 360 and installed. After a few weeks I took it off... overall speed of the computer was terrible. Any ideas???

I have noticed that most anti-virus programs out there do slow down the computer but it is only because of the active monitoring they do. I use AVG and suggest it to many people as being a reliable anti-virus but, even that program has been causing "older systems" to slow down. I think there is no work around for finding a fast performing anti-virus (on older system) because in order to be an affective anti-virus they need to actively monitor your computer in order to protect you. Self knowledge also helps with protection on your computer. I hear from people all the time, "What is the best protection for my computer," To me besides having the right protection software is "Self Knowledge". There is no substitute for knowing the do's and don'ts for web browsing. The admins here have provided a lot of useful information on the "Do's and Don'ts" for browsing. I suggest for people to check out these sites and educate themselves so they know what they are doing wrong. Perhaps I have somewhat strayed from the question...

Getting back on track... the anti-viruses today require more system power so in order to really have an anti-virus work better you need a better system that can support it better. IMO.

My personal choice is NOD32 Anti-Virus if choosing a paid for program or avast! Home Edition Anti-virus if choosing a free one.

I also recommend avast!, another good one is Avira.

I recommend Comodo CIS. I have been using the Comodo Suite AV for well over a year now and never had a problem and it is very light on my PC with no noticeable slow down at all. I used Avira prior to Comodo and CIS is faster than Avira.