Hi,
1. Were there any changes made on the computer prior to the issue?
2. What troubleshooting steps did you try?
Method 1:
Run the hardware and devices troubleshooter and to check if any hardware is causing an issue:
http://windows.microsoft.com/en-us/windows7/Open-the-Hardware-and-Devices-troubleshooter
Method 2:
I would suggest you to refer to the link and try to update the drivers for the hardware devices:
Update a driver for hardware that isn't working properly
http://windows.microsoft.com/en-us/windows7/Update-a-driver-for-hardware-that-isnt-working-properly
I would suggest you to disable and re-enable the USB controllers:
a. Click Start, and then click Run.
b. Type “**devmgmt.msc”**without quotes, and then click OK. Device Manager opens.
c. Expand Universal Serial Bus controllers.
Note: You might have to scroll down the list to find this item.
d. Right click the first USB controller under Universal Serial Bus controllers, and then click Uninstall to remove it.
e. Repeat step 4 for each USB controller that is listed under Universal Serial Bus controllers.
Note: Restart the computer. After the computer starts, Windows will automatically scan for hardware changes and reinstall all the USB controllers that you uninstalled.
Let us know if it helps.