portable antivirus
Kaspersky Virus Removal Tool
Kaspersky Virus Removal Tool is a freely downloadable Virus Removal Tool. Although it does not provide real time protection from Viruses and can not stop a threat from entering your system, this Kaspersky Virus Removal Tool can be used scan for, disinfect, and remove existing Viruses or infections that may currently reside on your PC.
HiJackFree Malware Scanner
a-squared HiJackFree, now called "Emergency Kit" is a Malware Scanner and informative system analysis tool that advanced users and administrators can use to help detect and then remove all types of Malware; HiJackers, Spyware, Adware, Trojans and Worms. It can be used to manage autoruns, processes and associated modules, control Browser Plugins, and view all DNS entries.
Sophos Anti-Rootkit - Removal Tool
Sophos Anti-Rootkit is a portable tool that can be used to discover and remove any rootkit that may reside in a computers running processes, registry or on a local hard drive. A rootkit also known as (Root Kit) is basically a set of tools that are used to conceal a malicious program from the computer user.