When trying to remove printer drivers on a Windows Server 2012 R2 Remote Desktop Session Host server the following message is displayed “The specified printer driver is currently in use” and the driver is not removed.

Workaround:

1. Open the registry editor.
2. Go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Print\Providers\Client Side Rendering Print Provider.
3. From Servers\<printservername>\Printers\ delete the {GUID} folders where the “Printer Drivers” REG_SZ value references the printer driver to delete.
4. May not be necessary. From all the S-1-5-21-* delete the Printers\Connections\,,<printerservername>,Printername of the printer that was deleted.
5. Restart the Print Spooler service.
6. It should now be possible to remove the driver.

Source: Eversity - “The specified printer driver is currently in use” error is shown when removing a printer driver in Windows Server 2008 R2