Hey there Br4tt3, Thanks for taking the time to reply. I actaully posted to the WinPE newsgroups @ M$ as well this question (with more detail) <SNIP> This is particularly important for me as I have Compaq servers with the 44MB system partition, then I need to create 2 extra partitions as C and D, but the issue is that the CDRom will already have taken D drive, so my new partition ends up as C and E. I am aware I can use DiskPart to change the CD drive letter, but this is not helpful as I have to reboot after the change which is time consuming and causes more scripting as I am trying to do this automagically. It would be far easier to be able to force the PE CD to default to a particular drive letter. <\SNIP> ...and I got this following reply... <SNIP> WinPE will assign itself the next available drive letter there is nothing that can be done to change this. The drive letters assigned while running WinPE will not be the same assignments once the OS is installed to the drive. Regardless if you assign the second partition as letter E: after a single reboot it will be seen as drive D: and WinPE will be moved up to letter E: <\SNIP> I will do some more testing around this theory, but I was pretty sure from my initial testing that this wasn't the case....but as I said, I will test it more thoroughly to see the outcome. I'll post my results once I get this done.