Some users have reported an issue in which Windows 7 computers that are connected to Active Directory domains crash when users attempt to unlock them. A poster to the Microsoft TechNet discussion forums writes:
“The computer is connected to an Active Directory domain, and I lock it every time I leave my desk. Unfortunately when I come back and unlock it, 90% of the time, lsass.exe has crashed, and the PC reboots a minute later.”
The problem appears to only occur when the system is connected to an Active Directory domain.