I have 2 , Server 2008R2 boxes as members of a Terminal Server farm. I can use the printui.dll command "Rundll32 printui.dll,PrintUIEntry /ga /c\" to successfully add printers globally to one of the machines. (The printers reside on our print server). The second machine I cannot remove or add any additional printers. I used to be able to until after I deleted a few of the "Inactive TS ports" when trying to diagnose an issue with my HP Universal Print driver.
Even manually adding the printer through the print wizard fails.
I would like to add the printer for each user on the terminal server without resorting to a Group Policy implementation for printing. (which i suspect on this box would fail as well since I cannot manually add the printer).