Here's an interesting OSD related issue I got from Vinay Pamnani, a Support Engineer in our Manageability group. If all your Vista or Win2K8 deployments mysteriously end up on the D drive then maybe this is your issue:
Issue: When deploying Windows Vista or Windows Server 2008 via OSD, the installed operating system shows up on D: instead of C:
During the PE phase, the Task Sequence says its formatting C: and the SCCM Task Sequence Log says everything is going/installing on C:. The only thing is that when Windows comes up everything is on D:. Even after setting the location where it installs to in the Task Sequence, to 'Next available formatted partition' / Specific logical drive letter / Specific disk and partition', the same behavior is seen.
Cause: This happens if you use the install.wim (which is shipped on the Vista\Server 2008 Installation Media) to create the Image Package in order to deploy the OS.
Resolution: The solution in this case would be to capture an image and then deploy the captured image to ensure that the OS is installed on the C:
Here' the link which explains why this happens: http://blogs.technet.com/inside_osd/archive/2007/08/08/why-does-vista-end-up-on-the-d-drive.aspx
Here's an excerpt from the above link which explains it all:
Several people have tried to use the install.wim from the Windows Vista installation media in an Install an existing image package task sequence. They are surprised to discover that, upon completion, the operating system is on the D: drive instead of the C: drive. The short explanation for why this happens is that the operating system volume for the images in install.wim is D:. In other words, when the image was captured, the reference machine had the operating system on volume D:. Why this is the case for the install.wim that ships on the Windows Vista installation media is beyond the scope of this blog.
The supported method for generating an image which can be used in an Install an existing image package task sequence is to capture an image of a reference machine, which can be built manually or using the Build and capture a reference operating system image task sequence.
J.C. Hornbeck | Manageability Knowledge Engineer