Remove the BDEDrive partition

MDT creates a partition named BDEDrive when it installs Windows OS. This drive is used with Bitlocker to boot the OS. If Bitlocker never will be used the BDEDrive can be removed using the following procedure:

1. Start an elevated command promt and execute the following command to copy startup files to the C-drive:
bcdboot C:Windows /s C:
2. Set partition C: as active:
diskpart
list disk
select disk 0
list part
select part 1
active part
3. Reboot the computer:
shutdown -r -t 0
4. Delete the BCD Drive:
diskpart
list disk
select disk 0
list part
select part 2
delete part

There is a more indepth explanation at the following site:
http://aikitsupport.com/bde-drive-removal/