USB flash drive not present in My Computer or Disk Manager

We've got a user who is having problems accessing the contents of his
USB flash drive. The funny thing is that, though Windows makes the
standard "new hardware found" sound and a dialog balloon from the
system tray states that new hardware has been detected, the drive does
not appear in My Computer or Disk Management in the MMC (no drive
letter, no disk without a drive letter). In Device Manager, however,
"Generic Volume" does appear.

Additionally, every time we attempt to remove the USB flash drive
through the standard "safely remove hardware" routine, we will tell it
to "stop" the device, but then the process will hang, and the device
will not be "stopped". After that happened, the user physically
removed the flash drive without waiting for the drive to be "stopped".
This caused some of his other USB devices to stop functioning,
including his USB data link between his PC tower and his smart phone.

We have uninstalled all USB drivers as well as the "generic volume"
and performed a reboot, and that didn't do anything. He did have a USB
hub plugged into one of the ports, but we removed both the physical
device as well as the hub "driver" from device manager. We are still
unable to see the drive in either My Computer or Disk Management in
any form. Any ideas as to what might be the problem?

Thanks,
Dan

I always have to click save as then go to my computer and away and
back again for it to appear