One of the new feature that has been added in ConfigMgr 2012 SP1 (and updated to support 32-bit in CU1), is support for deploying Windows to computers that are configured to use UEFI.

I’m currently working on a Windows 8 deployment project, where one of the requirements was to support Windows 8 deployment to UEFI enabled devices. At this customer, we also integrated MDT 2012 with ConfigMgr 2012.

The configuration was easy, and PXE boot worked like a charm. But after the OS Image was downloaded the Task Sequence failed, and after a few minutes we found the problem.

The standard MDT 2012 Update 1 Task Sequence, has a bug when deploying Windows 8 to UEFI enabled devices. The default “Apply Operating System Image”, has the destination configured to use “Logical drive letter stored in a variable” = “OSDisk”.

The only problem with that is that when the disk is formatted using the new Format and Partition Disk (UEFI) step, the OSDisk variable is not configured. All other format steps has this variable configured, so I guess they just forgot this one.

Steps to fix this bug:

  1. Edit the MDT Task Sequence.
  2. Locate and select the “Format and Partition Disk (UEFI)” step.
    (Preinstall -> New Computer Only -> Format Disk).
  3. Select the Volume: “OSDisk (Primary)”, and click Properties.
  4. Under Advanced options, set the variable to “OSDisk”.

Update: I’ve asked Microsoft about this issue, and they have just confirmed this bug. This bug will get fixed in the next release of the MDT.


+Ronni Pedersen