Actually, I have found the best approach is to make use of a Rescue Disk. Boot from the Rescue Disk to scan and remove threats from an infected computer without the risk of infecting other files or computers. Burn this ISO image to a CD, insert it into the infected system's CD-ROM drive, enter the PC's BIOS, set it to boot from the CD and reboot the computer.
Download
kav rescue 10 .iso here
http://devbuilds.kaspersky-labs.com/devbuilds/RescueDisk10/ (27 June 2010)
Kaspersky Rescue Disk , a bootable DOS Based Kaspersky Antivirus used to perform virus scanning and remove viruses without booting the operating system first. Using Kaspersky rescue disk to remove virus is considered the safest way without risking your computer OS getting infected again.
Kaspersky Rescue Disk is able to remove known viruses, trojans, worms and other malicious software just like Desktop Kaspersky Antivirus. Plus more, any computer with a CD rom can use Kaspersky rescue disk to scan their computer hard disk because it's totally independent from the installed operating system. However, Kaspersky Rescue Disk has a limitation or disadvantage. The virus definitions cannot be updated. This means any Kaspersky virus definition update requires downloading a full boot disk and burning it to CD again.
The best part is you can download kaspersky Rescue Disk freely and burn the DOS based anti virus into bootable CD media.
Howto Use kaspersky Rescue Disk as Bootable DOS Antivirus:
1. Download Kaspersky Rescue Disk ISO file
2. Burn the Kaspersky Rescue Disk ISO image to a CD media using CD/DVD burning software.
3. Once finished burning Kaspersky Rescue Disk into bootable CD media, insert Bootable kaspersky Rescue Disk CD into CD ROM and boot the computer by loading CD ROM media first.
4. Then a DOS screen will be loaded below. Hit Enter to start booting the DOS Kaspersky AntiVirus using Linux.
5. Finally a Kaspersky AntiVirus 2009 GUI will be appear. Just check the hard drives that you want to scan virus or other malicious thread.