I’ve wanted to shrink the primary partition on a couple of workstation in order to install other operating systems (Linux) alongside Windows 7. In order to do this, the BDEDrive partition needs to go.
This partition is created by MDT by default, but can be disabled in a setting (DoNotCreateExtraPartition=YES in customsettings.ini).
I haven’t really done any research on what the partition is for. I’m assuming BitLocker which I don’t use anyway.
Here’s how you get rid of BDEDrive:
bcdboot c:\windows /s c:
Now, feel free to delete the BDEDrive partition. Remember to mark your Windows partition as Active before rebooting.