"A recent update to Symantec's antivirus software rendered some Windows-based PCs inoperable, the security software maker disclosed Friday.
An update earlier this week to Symantec Endpoint Protection 12.1
antivirus software for businesses caused some Windows XP-based computers
to crash repeatedly with a "blue screen of death," the company revealed
on its Web site.
"On July 11th, 2012 Symantec Security Response started receiving reports
of customers experiencing blue screens after applying the July 11th
revision 18 definitions," Orla Cox, of Symantec Security Response, wrote in the post. "Machines may continue to blue screen after they reboot. This problem only appears to occur on Windows XP machines.""