When you’re deploying an WIM image using System Center Configuration Manager 2012, by default the installation is done on the D:\ partition of your system. Huh….D:\ partition?? But my task sequence say C:\?? Yes indead!! During the task sequence you’ll see “applying image 1 to C:\”, but after rebooting the system, there is no C:\ drive!! Only a D:\ drive!!
To fix this problem, you’ll need to add a new task within the task sequence.
1.) Open the System Center Configuration Manager 2012 Console
2.) Navigate to the task sequence and click Edit
3.) After the partition task, add a new task named Set Task Sequence Variable
4.) The name of the Task Sequence Variable is: Disable Disk Drive Letter (this can be anything you want!)
5.) The Task Sequence Variable will be: OSDPreserveDriveLetter
6.) The value will be: False
7.) Just PXE boot the machine again and watch te result!