McAfee a global leader in Antivirus solutions also has their own free AVERT Stinger portable virus removal tool that can easily be run from a portable USB device. This utility is typically used by users and administrators to help deal with and repair infected computer systems. Stinger utilizes next generation scan engine technology, including process scanning, digitally signed DAT files, and scan performance optimizations.
McAfee Stinger Screenshot
Authors Website: Avert Stinger Home Page
Download: Grab the latest Stinger release from HERE