Not too sure if we can recover from this state.
I've put my machine in this state but even with getting the drive letter looking good with DISKPART. It continues to use D: for Windows boot partition.
Let's see if your device is doing the same thing. Here's the easiest place to check
Find the drive letter your Windows is on.
Notepad
File - Open
D:\ProgramData\Microsoft\Windows\WER{Some directory}\Report.wer
Open
The LoadedModule does it show C:\Windows or some other letter?