Specified Port is Unknown error when adding Network Printers

Just finished investigating and resolving an error whereby the message ‘Specified Port is Unknown’ appears when adding a network printer. This was first noticed when running a login script that add’s printers didn’t actually add any printers.

To fix this problem, you need to delete references to the printer drivers in the registry. I had already deleted any references to any network printers in an earlier attempt to fix the problem, so I wil;l include that as a step as it will not affect any functionality.

  1. Open Registry Editor, making sure that you have administrator rights.
  2. Expand HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Print\Environments\Architecture\Drivers\Version-3
  3. Delete any subkeys for printer drivers that have been installed.
  4. Expand HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsNT\CurrentVersion\Print\Printers
  5. Delete any subkeys that reference any network printers.
  6. Close Registry Editor
  7. Restart the Print Spooler services

After this had been completed, all of the shared printers as part of the login script connected and functioned as they should.

All I can imagine is that one of the drivers was corrupt, or information had not been removed from the registry when a printer was removed.

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One thought on “Specified Port is Unknown error when adding Network Printers

  1. Worked like a charm. I was installing a networked, IPP printer on a Windows 2012 R2 server and got this error. After following your steps, the printer installed correctly. Much appreciated!

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