I've put together a list of freeware/liteware security tools from a larger list, including the best ones that can be put into your flashdrive and used for cleaning, diagnosis on infected systems. Almost all do not require installation, and are free.
I have selected antivirus, antispyware, antitrojan and antirootkits tools that are top notch, system tools, and as a bonus there is a list of links to the best online scanner sites, both multi-engine (virustotal etc) and full disk (Bitdefender online etc) as well as sandboxing type (Threatexpert etc).
You can find them at Security tools for usb
Any comments are welcome, particularly omissions.