A. Standard RDP has support for redirection of certain types of USB devices, but the support is quite limited. RemoteFX USB redirection supports most common types of USB devices. To enable it, you need to set the following policy, either through the computers local policy (gpedit.msc on you Windows 7 SP1 client) or through Group Policy, using an SP1 client to edit the policy.
Navigate to Computer Configuration, Administrative Templates, Windows Components, Remote Desktop Services, Remote Desktop Connection Client, RemoteFX USB Device Redirection and set Allow RDP redirection of other supported RemoteFX USB devices from this computer to Enabled. Set who should have RemoteFX USB redirection rights, then click OK and close the policy editor.
You now need to update the machine's policy using
from the command line. Then reboot the machine for the change to actually take effect and enable the RemoteFX USB redirection option in your Remote Desktop Connection client.
Once it's enabled, access the Local Resources tab, click More under Local devices and resources, and you'll see a new Other supports RemoteFX USB devices setting. You can use this setting to map through many types of USB hardware that you couldn't with vanilla RDP USB redirection, as shown below.
Check out this video to see RemoteFX in action.