USB Ports turned to 'Unknown Device' in device manager.

[AlexTheHopper]

Recently, all 4 of the USB3.0 ports on my laptop (MSI GS70 2OD (Stealth)) stopped working abruptly. I went and checked it out in the device manager and where there should be the ports, are only three 'Unknown Devices' which I assume are the ports. The devices say they're missing their drivers, I've spent ages looking on the net for answers and nothing has helped. Any help is appreciated!
Thanks,
Alex

 

[Abmario]

Unplug any devices connected to your USB 3.0, kb & mouse you may connect to USB 2.0 port.. Restart your laptop, then go to Device Manager again and see if still there..

You may also wanna try sfc /scannow: this will scan your system files for errors and fix it as possible
http://support.microsoft.com/kb/929833

If still nothing happens, you may refer to this:
http://www.sevenforums.com/tutorials/165554-usb-driver-general-fix-problems.html