I am gonna suggest you two procedures to try.
1. Disconnect all your USB devices, Go to Device Manager, expand "Universal Serial Bus Controllers". Uninstall all USB Host controllers. (Right click and uninstall). Also uninstall all other items such as hubs. Restart your computer. Windows 7 will will reinstall all the USB controllers automatically.
2.Assuming that this happens to your laptop, the following procedure seems to have been successful as tried and reported by many. Remove all USB devices.
1) Shut down your laptop.
2) Remove the powerbrick from the mains socket, if you are using it on mains power and also unplug it from your lappie.
3) Remove the battery pack of your laptop
4) Take a break, go have a cup of coffee/tea and then connect the battery pack again
5) Switch on your lappie and boot.
Hmmmm.........extending the logic ,the same may work with desktops too. Simply unplug your PC from the mains or from the UPS and let the charge on all capacitors drain. Plug it in after a minute or two and start your comp.
If you succeed do report here. Good luck.
