From LedHed's Wiki
Windows 7 automatic driver installation for printers requires that the user have Administrative privileges.
This is problematic if you have lots of users and need to centrally deploy new printers/drivers.
To disable this security feature create the following GPO:
Computer Configuration\Policies\Administrative Templates\Printers
Disable "Point and Print Restrictions"
Now link this GPO where appropriate.
Reference
http://technet.microsoft.com/en-us/library/cc753269.aspx#BKMK_GPLimitServers