03 February 2012

MDT 2010 -- Failure (ERR):68: Ran diskpart to change drive letter - Device unavailable

This error, which occurs in both MDT 2010 and MDT 2012, is caused when the USB thumb drive is left in the USB port after the initial WinPE is loaded and the imaging process is initiated. Simply removing the USB thumb drive after WinPE loads corrects this error. Once the Task sequence wizard is loaded, everything has been loaded into memory from the USB, hence it can be removed. In the end, either ignore this error, or remove the thumb drive after WinPE loads.

This error is caused by the fact that the USB thumb drive is assigned the drive letter c: as the WinPE loads. During the initial Litetouch.wsf processes, it is checking to make sure c: is available for the drive letter where the OS will be laid down. If it is not available, the Litetouch.wsf will try and reassign a new drive letter to the thumb drive. It is at this point where the error occurs. It is an invalid error because when the system reboots, the drive letter is reassigned and c: is assigned to the primary HDD where the image is being laid down.


  1. I'm having this error and I'm running deployment from the network server not from USB. Any sugestions?

  2. Are you running it from a mapped drive or a UNC path?

  3. hi mike, when i am installing win7 through sccm 2012-MDT TS into existing computer, winpe assign C drive to bit locker partition, is there anyway that i can stop it?