What is a good, safe and free virus scanner i can use?

I think my computer may have a virus but for some reason the antivirus program i used to have has been deleted. does anyone know a good and safe one i can download?

What is a good, safe and free virus scanner i can use?norton ghost

avast!

What is a good, safe and free virus scanner i can use?software

AVG free edition is pretty good for anti virus and get ZoneAlarm firewall (free edition) on the side; I've had this combination for a long time and nothing gets in my computer, nothing gets out of my computer. www.download.com
Try AVG free edition @ http://free.grisoft.com there is bad parts about it though it only scans viruses no spyware,adware,and fissures.

i do have a free windows live care and it scans everything free

go to http://onecare.live.com/site/en-US/defau...

Then click protection(on the left side of the page). Then click protection scan.P.S. it takes a while for windows live care to scan but it scans for everything not just viruses.
I have found that Avast is one of the best on the free market today.
Active Virus Shield is free anti-virus for your PC that combines traditional antivirus programs, stopping them before they can infect your computer.

* Real-Time File Protection. All individual files, catalogs and disks can be scanned for viruses or, to cut down on scan times, Active Virus Shield allows users to focus attention only on critical areas of the operating system. In either case, Active Virus Shield serves as a watch-dog, continuously monitoring and helping to protect files. Active Virus Shield can also scan faster by scanning only new and changed files.