USB devices are automatically redirected when USB support is enabled, and the USB user preference settings are set to automatically connect USB devices.
In Receiver for Windows 4.2, USB devices are also automatically redirected when operating in Desktop Appliance mode, and the connection bar is not present. In earlier versions of Receiver for Windows, USB devices are also automatically redirected when operating in a desktop appliance mode or with Virtual Machine (VM) hosted applications.
However, it is not always best to redirect all USB devices.
Some applications are not able to see the redirected USB devices because they were redirected in an optimized mode.
To overcome this problem it is possible to redirect the USB device as a generic USB device. Keep in mind that the generic driver must be installed on te VDI.
With the desktop viewer installed with the Citrix receiver you can easilly switch between optimized and generic. However most companies do not allow the desktop viewer to be installed. Without the desktop viewer it is not possible to switch between the generic and optimized mode.
To force the USB device to be redirected as a generic device the following registry key must be created on the client device.
[HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\ICA Client\GenericUSB\Devices\VID**** PID****]
Replace the VID**** with the vendor identifier and the PID**** with the product identifier. These hexadecimal numbers can be found in Device Manager.
I hope this help you guys with solving some of the USB redirection problems. If not leave a message.