What's the best anti virus software for free?

i really need some good antivirus, but it has to be for free, i already have mcaffee and avast, but they arent picking up on the whole virus, i think its a trojan, and it keeps on changing my homepage to a spyware filled page called safetyhomepage.com, and i cant seem to get rid of it, what do i do?

What's the best anti virus software for free?security

鈽呪槄 SECURITY SOFTWARE %26 TIPS 鈽呪槄

鈼?The very best virus scanners are free. Mcafee %26 Norton Antivirus are mostly hype and won't do as good as the free ones. -- About.com %26 Smart Computing Magazine

鈼?Download and install AVG. Use it first and see if it finds any viruses or trojans.

鈽?http://free.grisoft.com/doc/1

鈼?After running AVG go here and run this virus scanner online. There is no need to install it on your computer.

鈽?http://housecall.trendmicro.com/

鈼?Microsoft's New Live Safety Center. Download this scanner to check and remove spyware, viruses, get rid of obsolete files and junk off your computer, and improve your PCs performance.

鈽?http://safety.live.com/site/en-US/defaul...

鈼?The Microsoft Windows Malicious Software Removal Tool checks computers running Windows XP, Windows 2000, and Windows Server 2003 for infections by specific, prevalent malicious software鈥攊ncluding Blaster, Sasser, and Mydoom鈥攁nd helps remove any infection found. When the detection and removal process is complete, the tool displays a report describing the outcome, including which, if any, malicious software was detected and removed. You can run this tool online FREE.