Due to the tyranny of time zones, I've just come onto this thread. I'm one of the Linux guys and I'll still offer my 2 cents worth.
I'm putting in a plug for the Kaspersky Rescue Disk. It's a free, Linux based, self booting CD. with the Kaspersky anti-virus on it. As soon as you boot it, you can click on the update tab and it downloads the latest updates.
I was given an infected WinXP laptop, which had been scanned by numerous Windows anti-virus programs but was still playing up. I booted the Kaspersky CD, updated the data base and started scanning, Several hours later, Kaspersky reported 69 viruses that none of the Windows anti-virus programs had found.
The beauty of this program was that once the viruses were cleaned, the laptop was handed back to the owner with all its operating system and data intact.


tony
Lenovo lappie, 4Gb RAM, 500Gb HD
Ubuntu 12.04
Running BIAB under WINE