Of course the problem with this approach is that a DVD or USB stick will always start with the same virus database. If your system is already infected with malware then this makes it far more likely that you'll be able to remove it successfully, as the malware won't be running and so cannot apply any tricks to hide from the scan, or prevent itself from being deleted. Burn this to a DVD or unpack to a USB stick and you should be able to boot your PC from it.
Kaspersky Rescue Disk is a free bootable environment that will detect and remove malware from a badly infected PC.
