The Directory pruning priority machine setting should be configured correctly. The pruning thread, which runs only on domain controllers, deletes printer objects from Active Directory if the printer that published the object does not respond to contact attempts. This process keeps printer information in Active Directory current. The thread priority influences the order in which the thread receives processor time and determines how likely it is to be preempted by higher priority threads. Fix: (1) GPO: Computer Configuration\Administrative Templates\Printers\Directory pruning priority (2) KEY: HKLM\Software\Policies\Microsoft\Windows NT\Printers\PruningPriority