That's sounds correct Phurios, but I was under the impression that PE should actually be able to deal with the Drive letters as they are already known.
It seems to be naming them under it's own way.
This fact can actually be read in the official Win PE documentation.
The drive letter assignments are NOT read from the OS on the disk, they are assigned like a fresh install would assign them - with one exception: if you boot PE from your hard disk, that partition will get X:, and the rest will get the available letters from C:.
Hard Drive Partitions
in Windows PE
Posted
This fact can actually be read in the official Win PE documentation.
The drive letter assignments are NOT read from the OS on the disk, they are assigned like a fresh install would assign them - with one exception: if you boot PE from your hard disk, that partition will get X:, and the rest will get the available letters from C:.