After a recent update Windows 10 displays the EFI System Partition (ESP) under This PC together it an assigned drive letter, while the drive does not have an associated letter under Disk Management. A screenshot of Disk Management which is accessible by typing diskmgmt.msc in the start menu or Windows run prompt is given below:

As it is evident from the screenshot above there is no drive letter assignment to the EFI System Partition, however it appears under This PC with a drive letter as seen below!

In order to remedy this situation some tweak should be made from an elevated command prompt. From now on please proceed at your own risk and be extremely prudent not to make unsolicited changes.

To access the administrator command prompt follow these steps: Start Menu -> Type “cmd” -> Right click and select “Run as administrator”. Now the following command should be run to identify the disk:

diskpart
list disk

After the disk is identified (replace 0 if the disk is different) the following command should be run to select the disk and identify the ESP partition

select disk 0
list volume

After the volume is identified (it is 1 in my case) the following commands should be run to remove the drive letter (G in my case) assignment.

select volume 1
remove letter=G

After these steps are done the drive letter should be remove and it can be checked on the command prompt with the following command whose output is given in the subsequent screen shot. Type “exit” to exit diskpart.

detail partition

However, to render these change permanent there is one additional step and it is to launch the Registry Editor and delete the corresponding mount action. After doing the following steps and rebooting the changes should be permanent.

• Open Registry Editor -> Type regedit in the start menu
• Navigate to Computer\HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices
• Delete the corresponding REG_BINARY value corresponding to the drive key in the registry (i.e. \DosDevices\G:)