I did a very stupid thing. I removed the following files from C:\WINDOWS\inf: usbstor.inf, usb.pnf, usbstor.pnf, usbport.pnf to a different location. I then uninstalled all 5 USB Root Hubs via Device Manager. After restart all USB devices including the keyboard and mouse are not working anymore. The worse thing of it all is I don't have the disc drivers anymore. Any suggestions?