OK so you’ve deployed Windows 7 to your clients and you have not given them local administrator rights (damn right in an enterprise environment).
However non administrator rights means no printer installations without a UAC prompt for admin credentials – which can prove a thorn in the side, especially if your users move around a lot and need to install printers at various locations.

This can be addressed via group policy.
I have managed to allow non-administrators to install network printers on their local machines by applying the following single GPO which apply these two settings:

Computer Configuration -> Policies -> Administrative Templates -> System/Driver Installation
Allow non-administrators to install drivers for these device setup classes = Enabled
     Allow Users to install device drivers for these classes:
          {4D36E979-E325-11CE-BFC1-08002BE10318}
          {8FCEE422-B109-4758-9A6E-5BAB7B37996F}

Computer Configuration -> Policies -> Administrative Templates -> Printers
Point and Print Restrictions = Disabled