First, are you sure you are getting into Safe Mode. It should say so in each cornor
of the screen after you kill the System Information program.
Sounds worse than I expected. The installed virus scan could have been damaged
by the virus to prevent them running. Download the McAfee Stinger program (link in
prior note) and copy it to a diskette. Then run Stinger on the system directly from
the diskette. It should be able to remove enough virus programs so that you can boot
into safe mode and run his AV program.
