Install the AMD Chipset driver and reboot:
http://support.amd.com/en-us/download/chipset?os=Windows 7 - 64
If you still need USB after installing Chipset>>AMD USB 3.0 Driver
Install the AMD Chipset driver and reboot:
http://support.amd.com/en-us/download/chipset?os=Windows 7 - 64
If you still need USB after installing Chipset>>AMD USB 3.0 Driver