This looks very much like it belongs in the Business section. If you don't already have McAfee, the best place for it to start with is probably in the General Discussion section.
Moved to Malware Discussion > Corporate User Assistance as possibly more appropriate than Community Help.
Amy, sorry to hear it. Those machines are going to need to be re-imaged and their BIOS's flashed. There's no way around it, I'm afraid. No AV vendor is going to be able to reliably clean up anything like that.
LANDesk and Altiris (now owned by Symantec) both have fairly comprehensive systems management suite that once installed can facilitate remote and mass re-imaging. McAfee doesn't really play in this space yet, best I can tell, which is perhaps why the only help you got here was moving the thread somewhere else.
As for the BIOS re-flashing... that may be something that has to be done in person at the console.
For the benefit of others who support such environments, I'd love to hear some lessons learned from this infection and some details on it. It sounds extremely nasty.