So this is a very frustrating problem I've come across. I need to use my USB to transfer files from my desktop to my laptop as I leave for a business trip soon. The timing of this USB failure is somewhat of a Twlight Zone situation, but I digress: When I plug any USB flash drive into any port on my PC, it recognizes that it's plugged in, however, it does not assign it to a drive. When I go to disk management, it lists only my disc drives; not even my hard drive! As you can see, this clearly makes no sense. So if anyone has any idea of what could be the issue here, please tell me.
Try this sometimes it works, when removing your usb drives do you just pull them out or do you properly remove them from your deivice plugged in devices the utility for that is on the lower right had side has a little green check mark click on it and disable/disconnect any added external drives. Once it says it is now safe to remove, do so, power down your system unplug it from the wall, if laptop remove battery pack as well. Wait ten minutes, power back up, try putting the usb drive back in and see if it reads it. The purpose of powering down in this manner is to clear all cache memory and temp settings, this has often worked for me if it still doesn't work go to device manager right click on the top usb connection in the usb device tree and click on scan for changes. One special note many people push in and pull out thier usb devices and in many cases leave static electrical build up in the drive this can damage your usb ports and/or usb drives. If none of these options work try connecting your camera, mp3 player see if they are recognized this will at least tell you if your usbs are working properly. Here are some google search links that may help you http://www.google.com/search?q=trou...&rls=com.microsoft:en-us:IE-SearchBox&ie=&oe=
