We’re going to use the built in partitioning tool called diskpart to confirm that:

  1. We have all the right partitions
  2. EFI partition is formatted correctly.

In the black screen that looks like a dark abyss, type:


and enter this command:

sel disk 0

Now that the first disk is selected we need to view all the partitions

list vol

Windows 8 diskpart

Verify that the EFI partition is using the FAT32 file system then select the volume and assign a drive letter to it.

Since i’m using Windows 8 from a VirtualBox image you won’t see the FAT32 partition on the screenshot above; but on yours you can select it by noting the Volume Number.

1. Assign the Drive Letter

Let’s say your EFI partition is on Volume 3, the next thing you would type is:

sel vol 3

Then assign an arbitrary drive letter to the partition.  Let’s use v.

assign letter=v:

You should see a message saying: DiskPart successfully assigned the drive letter or mount point.

Exit the diskpart tool by typing:


You should still be in the command prompt but outside of the DISKPART> prompt.

The reason I’m creating this post is because I formatted my entire 500GB USB drive as a Primary System Partition, which results in Windows not being able to format it through explorer or command prompt. What’s the solution? In my opinion it’s…

EaseUS Partition Manager (Portable Premium Version)

THOUGH… Even after using EaseUS I was able to SEE the drive but I still cannot fix it completely…

Updates will be coming as I find a way… !!!