Delete a Protected EFI Partition
If you try to format a Mac HFS (HFS+) formatted drive with the Windows Disk Management tool, you'll discover a stubborn EFI partition that evades all attempts to delete it! The secret is to use Diskpart and the clean command (from the cmd prompt).
How to delete a protected EFI disk partition in Windows 7, 8, or 10:
1 Open 'Disk Management': click the Start button, right-click on Computer, and choose Manage from the menu.
Or, navigate to: Control Panel ➤ Computer Management ➤ Storage ➤ Disk Management
Here we can see the EFI partition (on Disk 1):
2 Open a cmd window, and run DiskPart. Select the disk, here 'Disk 1', and 'clean' it:
Note: your 'disk number' may be different. Check, double check, and check again!
Microsoft Windows [Version 6.1.7601] Copyright (c) 2009 Microsoft Corporation. All rights reserved. C:\Users\Mike>diskpart Microsoft DiskPart version 6.1.7601 Copyright (C) 1999-2008 Microsoft Corporation. On computer: MIKE-HP DISKPART> list disk ⇐ display a list of 'objects' Disk ### Status Size Free Dyn Gpt -------- ------------- ------- ------- --- --- Disk 0 Online 465 GB 0 B Disk 1 Online 931 GB 931 GB * DISKPART> select disk 1 ⇐ shift focus to an object - be 100% sure it's the right one! Disk 1 is now the selected disk. DISKPART> clean ⇐ clear all information off the disk. Destructive! DiskPart succeeded in cleaning the disk. DISKPART> exit ⇐ leave DiskPart Leaving DiskPart... C:\Users\Mike>
3 The disk can now be initialised, and formatted in the Windows Disk Management tool.
Select the MBR (Master Boot Record) partition style, and NTFS file system.
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The formatted disk (Disk 1) now comprises a single healthy NTFS partition: