Use UEFI Detection for MDT 2010

Lately more and more vendors are using UEFI on their models which replaces the standard BIOS.

one big difference we need to consider when we’re installing OS on a UEFI based computer is that we cannot format the HD using MBR partition style, but GPT (GUID PARTITION TABLE).

when it comes to a central OS deployment with MDT or SCCM we can run in to some issues with the Task Sequence automation.
some of you probably ran into this error during Windows 7 TS Deployment:

“Windows cannot be installed to this disk, the selection disk has an MBR partition table. On EFI systems, Windows can only be installed to GPT disks.”

that’s because the disk has been formated automatically in MBR.

Good news. MDT 2012 supports UEFI  and can automatically deal with that kind of problem.

but if you want to continue have MDT 2010 and you want to be able to distinguish  UEFI models to format disk in GPT style  there’s no built-in solution by design, and there’s no WMI Query to identify UEFI.

thanks to Richard Mueller’s post, there’s a file named DetectEfi.exe that can be run from WinPE from command line which returns “UEFI” if UEFI support enabled and “LEGACY” if BIOS support enabled. (works only for x64 systems only). but how can we use it during task sequence?

here’s the solution:

1. 
   
   download the DetectEFI.exe and copy it to your scripts folder (DeploymentShare$\Scripts). 


2. 
   
   Create a new file named DetectEFI.wsf and paste the following code and copy it to your scripts folder.
   

   DetectUEFI
   

“>

This will create an MDT variable named UEFI.

Edit your MDT Task sequence. above Format and Partition Disk
add a Run Command Line task as the following:
Name: Detect UEFI
Command Line: cscript.exe “%SCRIPTROOT%\DetectEFI.wsf”

Edit the Format and Partition Disk task as the following:
Name: Format and Partition Disk MBR
Disk Type: Standard (MBR)
Options: task sequence variable UEFI equals No

add another Format and Partition Disk task with the following:
Name: Format and Partition Disk GPT
Disk Type: Standard (MBR)
Options: task sequence variable UEFI equals Yes

Save the Task Sequence and run the deployment again.

Now you are able to run the OS deploy with an auto detection and auto format task GPT \ MBR depending whether you have UEFI or not.

Source: http://blogs.microsoft.co.il/u-btech/2012/05/06/use-uefi-detection-for-mdt-2010/