[Locke]

Take a look at BartPE - a slick way of creating a bootable CD which you can add antivirus and antispyware apps to.

This *does* require a clean machine to download the PEBuilder app to (PEBuilder creates the boot disk image from software you already have or can download, thus avoiding legal trouble from redistributing code)

Then burn the bootable CD image it creates and use the CD to start thr infected computer. You can then run apps like Ad-Aware, McAfee Stinger, etc. against the hard drive without any hostile code active.