Instead of Update Driver, right click and select Uninstall. Reboot. The disk will be re-enumerated and storage volume re-detected. Any better luck?
If still no luck, See if this might help How to Cleanup and Remove old USB Mass Storage Drivers
Drive cleanup: What ComputerGeek has advised above:
Plugout all external Hdds/pen drives/USB Hubs/USB printers/Everything on the USB ports except your USB Keyboard and USB mouse.
Download v 0.8.1 of the drivecleanup.zip from Drive Tools for Windows.
Unzip it to a folder, say drivecleanup.
You will have two folders Win32 and x64 each containing DriveCleanup.exe for 32 bit and 64 bit respectively.
Remove all USB storage devices from your system (except your Keyboard and mouse) and reboot.
Right click on the DriveCleanup.exe and run as administrator. (Use the *.exe file appropriate for your bit version of Windows.).
After the cleanup, close the Window and then plug in your external drive.
If it does not resolve the problem
Try this:
Plugout all external Hdds/pen drives/USB Hubs/USB printers/Everything on the USB ports except your USB Keyboard and USB mouse.
Start > All Programs > Accessories > Right click on Command Prompt and Run as administrator.
Then
diskpart [ENTER]
Against the DISKPART prompt
automount [ENTER]
Does it say "automatic mounting of new volumes disabled" ? Then
automount enable [ENTER]
"automatic mounting of new volumes enabled
Close the Command Window and plug in your external drive. Problem resolved?
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