With ConfigMgr 2007/2012 I used the bdehdcfg tool to partition the drive after the OS installation was done. This creates the bitlocker partition at the end of the drive, marked as system and boot, without a drive letter.
With ConfigMgr 2012 R2 there is a new option "pre-provision BitLocker" before windows is installed and "Enable BitLocker" at the end. This benefit of this option is basically zero encryption time, compared to the old method I was using which would take about an hour on a good sized SSD.
This new method creates a 350mb system reserved partition at the start of the drive, marks as system and boot AND assigns a drive letter. In the task sequence the "Partition Disk 0 - BIOS" task is set to "do not assign a drive letter to this partition". It seems that checking/unchecking this box does not have any effect whatsoever.
I've tried with various scripts to remove this default partition but unfortunately no success. The scripts work when run from an administrative command prompt on the desktop, however when running during a task sequence I get an access denied error (4005)
Does anyone have a suggestion on how to remove the drive letter from this default partition and/or how to get the task sequence to actually abide to the checkbox at the partition stage?