Do not scan just Reboot ... You did Install the Chipset Driver ? ...
My Computer
- Computer Manufacturer/Model Number
- W530-3630QM1
- OS
- windows 7 home 64bit
- CPU
- INTEL-CORE I7
- Memory
- 16GB
- Hard Drives
- 750GB
- Browser
- Chrome
I can also try have a look. As for the Unknown Device (the XHCI controller) don't know if related either but have you tried installing the Asmedia USB 3.0 driver from ASUS web site?

What is the exact Model Number of your USB Adapter ? ...
Can you post your MotherBoard Model?
I am thinking it is your chipset driver that is having an issue.