I recently got myself a Belkin Wireless FSD7050 USB adapter for my Windows Server 2008 R2 test machine.
After installing the latest drivers from Belkin, the adapter is detected by Windows, but refuses to ‘enable’.
This is because wireless networking is disabled by default in Windows Server 2008 R2. To enable it, go to Server Manager > Features > Add Features > and add the Wireless LAN Service.
Also applies to: Windows Server 2008