Step 1. Hit "Windows Key + R to open the run dialogue box, enter "diskpart" and click "OK" to open a black command prompt window.

Step 2. Type "list disk" to display all the disks of your computer. Type "select disk n" to identify which disk you need to work with. Here n stands for the disk letter.

Step 3. Type "list partition" to display all the volumes on the hard drive. Type "select partition n" to identify which partition you want to remove. Here n stands for the volume letter.

Step 4. Type "delete partition override" to remove the EFI partition. Finally, type "exit" to close the windows when you receive the message says, DiskPart successfully deleted the selected partition".