USB Drives Disabled

by cswan at 2013-02-27 23:13:00

I am working on a project which in part will automate copying files from multiple SD memory cards to a hard drive. I was trying to find a way to use powershell to dismount/eject USB cards automatically for the user before he physically loads the next card. From the web, I copied and ran the following code which I thought would dismount the selected drive:

$vol = get-wmiobject -Class Win32_Volume | where{$_.Name -eq 'G:'}
$vol.DriveLetter = $null
$vol.Dismount($false, $false)

The drive along with all USB mass storage devices was removed and I have been unable to restore the USB mass storage devices. I am running Windows 7 and have rebooted, uninstalled the USB drivers and allowed the system to re-install. The USB ports function normally for other USB devices. The Device Manager - Portable Devices - WPD FileSystem Volume Driver - General tab/Device status "This device cannot start (Code 10)". I need 2 things - First and foremost to reverse the original code and restore use of the USB mass storage. Second, if possible - a way to eject USB cards so that another card can be re-installed immediately after removal. Thank you so much for any help you can offer.
by DonJ at 2013-02-28 09:19:57
Sounds like the mass storage profile drivers got unbound ;). The Dismount() method shouldn’t have done that, though, and without knowing what DID happen, I don’t have any suggestions for restoring functionality. You may end up having to do some serious OS-level repair. I suspect something went wrong with the Dismount() method. Not sure why DriveLetter would be set to $null… I’ve never done that. Anyway… fixing the problem is unfortunately a bit beyond the scope of PowerShell Q&A, but we’ll see if anyone else has any helpful suggestions for you!

In terms of doing this normally, I’ve always relied on the mountvol command. offers some other techniques I’ve seen people use in the past. There’s also a technique at that some of my customers use. All are adaptable to PowerShell.
by cswan at 2013-02-28 11:37:24
Problem Resolved. Used ‘USB Safely Remove’ (shareware) utility to re-establish original drive name.