The Directory pruning interval machine setting should be configured correctly. Specifies how often the pruning service on a domain controller contacts computers to verify that their printers are operational. The pruning service periodically contacts computers that have published printers. If a computer does not respond to the contact message (optionally, after repeated attempts), the pruning service "prunes" (deletes from Active Directory) printer objects the computer has published. By default, the pruning service contacts computers every eight hours and allows two repeated contact attempts before deleting printers from Active Directory. If you enable this setting, you can change the interval between contact attempts. If you do not configure or disable this setting the default values will be used. Fix: (1) GPO: Computer Configuration\Administrative Templates\Printers\Directory pruning interval (2) KEY: HKLM\Software\Policies\Microsoft\Windows NT\Printers\PruningInterval