In Windows Server 2008 domain, there are a set of built-in policies on removable storage access and installation. It makes restricting USB mass storage device more easier.

Open the Group policy Manager in your windows server 2008 and Do the following Steps, 

1. Computer Configuration-->Policies-->Administrative Templates-->System-->Removable Storage Access
 
    User Configuration-->Policies-->Administrative Templates-->System-->Removable Storage Access
 
It specify read and write permission on all kinds of removable storage device.
 
2. Computer Configuration-->Policies-->Administrative Templates-->System-->Device Installation-->Device Installation Restrictions
 
With device installation restrictions, the installation of removable storage device will be totally under control.