Those of you who deploy both x86 and x64 versions of Windows 7 using MDT 2010 Lite Touch probably know that you have to use two different boot images to do it:  When booted from a Lite Touch x86 boot image, you only see task sequences associated with x86 operating systems; when booted from a Lite Touch x64 boot image, you only see task sequences associated with x64 operating systems.

With MDT 2012 Beta 1, that’s been changed.  Now, if you boot from a Lite Touch x86 boot image you will see all task sequences, whether x86 or x64. 

But there is one “gotcha”:  If you choose a task sequence that deploys an x64 OS, MDT will need to find a copy of the corresponding x86 setup files and it will then use those to install the x64 OS.  So you need to make sure that you have x86 setup files in the deployment share (with one of the operating systems), even if you aren’t deploying that operating system.  It needs to match the version (e.g. 6.1.7601.17514) of the x64 OS that you are deploying.  (This is the really the same as if you were deploying a custom image.  Now, we just make sure we pick a copy of setup files that match the Windows PE platform being used, ignoring those that don’t, even if they are provided with the OS being deployed.)

The other combination, booting from an x64 boot image and deploying an x86 OS, isn’t supported by Windows Setup, so we still hide x86 task sequences when you have booted into an x64 boot image.