I recommend the Avira Antivir Rescue CD. It requires a blank CD-R (not CD-RW). It's a pretty big download of about 78 MB. It is an executable problem that writes the CD (there is also the CD iso image available for download).
Download the program
Put a blank CD-R in the CD writer
Double click the downloaded program
It should automatically start the set up to write the CD
Write the CD
Set the computer's BIOS to boot from the CD first.
Reboot the computer with the CD
The CD will ask if you want to download updates. Dependinging your imternet commection this may or may not be possible. The CD download is updated often and as long as it's a recent download it should be fairly up to date. It is easier to not try to download updates with the CD.
Perform a complete. full scan of the hard drive using the CD. Delete everything and anything it finds. Don't try to 'save" anything in quarantine.
When fthe scan is complete and infected files removed, shutdown the computer and remove the CD.