sccm 2012 sp1 cu01 MDT deploying Windows 7 OSD 32bit

ok, this is really getting pathetic.

Why are some OSD'd going to ANTHING other than C? I captured my original from a c:\ host machine not the media. 80% of new OSD'd are fine but out of the blue I get deployments to D, E, F what a frickin' joke! When i do a diskpart I noticed that the USB got C so I changed the drive letter and re-ran the task, no luck.

I never, not once had these problems with SCCM 2007.

What gives experts? How do I force OS on C?

Update: Just for grins I tried the Windows 8 32bit OSD and it installed correctly on the C drive.

Both images were captured from C and both Tasks / MDT are pretty much identical.

Any ideas?

Have you tried with Task Sequence variable OSDPreserveDriveLetter?

See: http://technet.microsoft.com/en-us/library/hh273375.aspx

By default in an MDT task sequence in ConfigMgr the bitlocker partition is assigned a drive letter, even though it shouldn't be, go in to the formatting steps and remove the checkbox to assign the bitlocker partition a drive letter.

Also make sure you've imported the Windows 7 Image as an "Operating System Image" rather than an "Operating System Installer"