Heretic2 writes: About 9:50AM all the XP machines in my office started rebooting, and coming up with an error "DCOM: something" followed by "Windows is going to shutdown." and no ability to login. Our IT personnel figured out this was caused by a bad.dat from McAfee pushed in an update (forums posts deleted no links). IT personnel then figured out how to reboot into safe mode, remove the bad McAfee.dat file, and disable MCAfee but it's a manual process across hundreds of computers for us. Luckily I wasn't using WindowsXP.