Strange Error from Commandline Task in MDT, diskpart, keep data partition after new deployment

Reminder to the actual problem:

This then led to my task finally doing what it is supposed to. The goal was to have a Windows 10 on a Windows 7 machine that has a large data partition without having to restore the the data partition after deployment. With a large number of machines this would be lots of wasted time.

The solution to this was found by paying Microsoft, however for others who run into such a problem, here the solution.

The Problem had to do with the fact the file that contained the diskpart command must have been on the partition that was formatted. If not that file then at least some information needed to finish the step inside the task sequence. This led I believe led to the error. I find that often with Microsoft products it is more believe than knowledge, as sometimes it is simply impossible to figure out what actually happened.

However, this is how the formatting issue was solved. Add the directory to the WinPE and then execute the diskpart command with the file that is actually on the X: partition:

To make sure the disk formatting tasks are not executed one has to set a variable: DoNotFormatAndPartition

Then update the image and things SHOULD work. With Microsoft this is always a SHOULD.