I'd certainly give MBAM (above) a try.
The below instructions are made for the situation where you can not download MBAM on the sick computer.
Download the installer on the good computer. (Save the installer file on the desktop.)
Install MBAM on the good computer. Once installed, update it. After it updates, find a folder (In Windows XP) "C:\Documents and Settings\All Users.WINDOWS\Application Data\Malwarebytes\Malwarebytes' Anti-Malware" (you will need to enable viewing hidden and system files in "folder options" to find it,) and in that folder locate the file "rules.ref". It will be ~3.5Mb. Copy and paste it to the desktop.
Rename the installer file mbam-setup.exe to something more random, say ukeranian.exe.
(The reason for doing this is that many of these rogue apps. will block this program from being installed. This may fool it.)
Transfer the renamed installer to a flash drive. Transfer the file "rules.ref" to the same flash drive.
Transfer the flash drive to the sick computer. Open the flash drive (if it doesn't auto-open) and double-click the setup file to install the program. (You may have to transfer the file to the desktop first.)
Once it is installed, go to the folder "C:\Program Files\Malwarebytes' Anti-Malware" and rename the file "mbam.exe" to something else. Say, ukeranian.exe, or 1234.exe. (Once it is renamed, the program will have to be run by double-clicking on that file from within the program files folder; the start shortcut will not work.)
This making sense so far?
Open the folder C:\Documents and Settings\All Users.WINDOWS\Application Data\Malwarebytes\Malwarebytes' Anti-Malware on the sick computer, and transfer the rules.ref file to it. "OK" the prompt asking you to replace the identical named file.
Disconnect the sick computer from the net. This can be done at any time, but do it now if it wasn't already.
Run MBAM by double-clicking the renamed file in the program files folder. Have it run a quick scan.
At the completion of the scan, place a tick beside everything detected, and select "remove selected". If you are prompted to reboot to complete removal, do so immediately. After reboot, run another quick scan to see if removal was successful.
Please post back, and post the scan report/s. (Before and after.)