If the computers can boot from USB, then you could make a bootable USB device using Kaspersky Rescue CD:
http://support.kaspersky.com/us/viruses/rescuedisk/main?qid=208286083
If they have Admin privileges on the systems in question, then you could also use Kaspersky's virus-removal tool from within Windows:
http://www.kaspersky.com/free-virus-removal-tool
For a system with no Internet access, also consider addressing the likely infection methods proactively.
1. arbitrarily disable AutoRun completely.
http://www.mechbgon.com/build/autoplay.html
2. enable the Windows Firewall if it isn't already.
3. lock down the Admin privileges. Anyone using the computer should be on a Standard User (non-Admin) user account.
4. lock down the execution of executables using either Family Safety, or Software Restriction Policy:
http://www.mechbgon.com/srp
5. it wouldn't hurt to install EMET 4.0, a free utility from Microsoft that makes it harder to exploit vulnerabilities in Windows and other software.