If you get the error:
Virtual Disk Service Error:
The operation is not supported by the object.
Make sure you’re disk is not a dynamic disk.
In mine case the disk was a dynamic disk en I converted it back to a basic disk, by using diskpart:
select disk 0
After converting the disk back to a basic disk I followed the steps on http://jaredheinrichs.com/how-to-delete-oem-partition.html