MDT Volume Could Not Be Locked During the Update

I’m trying to deploy Windows 7 using MDT. We had a custom image already built so we want to deploy just that image, and not bother with building any more W7 images using MDT.

Yet when I run the deployment, It installs the OS but when it reboots, there’s no boot device found.

Looking at BDD.log, I see this snippet after the OS install.

Return code from command = 0                                                                LTIApply
Property LTIDirtyOS is now = TRUE                                                           LTIApply
The image .10.2.35mdtOperating SystemsWindows 7 x86 - MackSourcesinstall.wim was applied successfully.     LTIApply
Event 5625 sent: The image .10.2.35mdtOperating SystemsWindows 7 x86 - MackSourcesinstall.wim was applied successfully.                                            LTIApply
About to run command: ".10.2.35mdtToolsX86bootsect.exe"  /nt60 C:                   LTIApply
Command has been started (process ID 1112)                                                  LTIApply
  Console > Target volumes will be updated with BOOTMGR compatible bootcode.                LTIApply
  Console > C: (\?Volume{2ca75f14-0000-0000-0000-401f00000000})                           LTIApply
  Console >     Updated NTFS filesystem bootcode.  The update may be unreliable since the   LTIApply
  Console >     volume could not be locked during the update:                               LTIApply
  Console >         Access is denied.                                                       LTIApply
  Console > Bootcode was successfully updated on all targeted volumes.                      LTIApply
Return code from command = 0                                                                LTIApply

I assume this is where the issue is coming from. It’s failing to update the bootloader information properly. Why?

Some info:

  • Client machine: OptiPlex 3010 (BIOS boot, NOT UEFI)
  • OS: Windows 7 x32 SP1
  • MDT/ADK/etc: Latest update (as of Oct 2021)