I know this may sound weird but i was having the same problem, my speakers and my mouse were both working fine, however my portable hard drive and other devices were making my computer just restart. So i was trying a bunch of differaant things to get it working again, i uninstalled my drivers, i updated them, everything. Then just kinda on accident i was playing with the usb connector, and it was finally working. All i did was put in the device, slowly about half way, then it made the connecting sound and it worked, it was strange. i dont know why this worked but maybe it can help you. just slowly put in the usb untill it reads, like i said about half way. hope this helps. Wow i didnt relize how long ago this was. lol. sorry i wasnt a little sooner.
