Real Stubborn, Un-Movable Mystery Drive Letter

Matthew Wai said:

The OP's drive E: should be the EFI system partition, which should not have a drive letter.

That's my thinking assuming it is the EFI system partition and not some HP thing.

Run CMD.exe on the program to open a Command Prompt window.
On the Command Prompt window, run the following commands and post the output:

DiskPart
List Disk
Select Disk 0
Detail Disk
list partition
Select volume X (X is the volume number of drive E:)

Caution: the following command will remove the drive letter E so as to hide the drive.

remove letter E

Matthew Wai said:

Run CMD.exe on the program to open a Command Prompt window.
On the Command Prompt window, run the following commands and post the output:

Ok I done list partition, see image, what next.

- - - Updated - - -

Sorted it, I think, ran "regedit", followed---- HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer.

Created new 32bit Dword/folder value, 16 in my case, restarted LT, drive letter E gone, it's still about somewhere, I've just hidden it but at least it won't bug me.