OU means for Organizational Unit. It is a container within Active Directory which can hold users, groups and computers. It is the smallest unit on which administrator can assign group policy settings.
BSOD stands for blue screen of death. When there is some fault in OS or hardware then Windows can’t run the program and gives a blue screen with a code. To resolve this problem the best way is to reboot the system. If it doesn’t work than boot the system in the safe mode.