My wife has a Toshiba Satellite laptop purchased late 2011 with four usb ports. Only one is working now and this apparently started this week as she performs a doc backup on Monday mornings and the port she uses worked last Monday but not today. We have tested them all, uninstalled them and had Win 7 re-install after restarting and still nothing on three of them. We have tried several devices to assure it's not a particular device. They show to be working properly in the device manager. Any ideas?