>To combat the viruses, our LAN is sending out logon McAfee update patches regularly, and asking all users to reboot several times a day. Of course that makes sense. But today, something went seriously wrong with an update, and now many machines are locking up after logon, resulting in downtimes, requiring LAN visits with bootup disks, etc.
>
>What a week, and TGIF.

I might be mistaken here, but if you don't do a scan/clean before rebooting that will just re-run the virus script with another round of emails going out.

It seems that the virus puts itself on your startup group.