Our fearless Engineer Brian was having a problem trying to add printer drivers to Windows Server 2008 R2, and he uncovered a fix for a grayed out "Additional Drivers" option. Try this as a fix:
- Open regedit
- HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionPoliciessystem
- Right-click a blank area in the right pane
- Click New
- Click DWORD Value
- Type: LocalAccountTokenFilterPolicy
- Double-click the item you just created
- Type 1 into the box
- Quit regedit, restart the server