Issue Bootable USB Flash on a Mac

I started with this video Create a Windows 10 Bootable USB Flash Drive on a Mac but i’ve not been able to finish the installation.

  • “dism /Image:D:\ /Add-Driver /driver:c:$WinPEDriver$ /recurse” outputs “Unable to access the image”.
  • Dir d: outputs “Device is not ready”
  • When I click ‘Next’ in the setup the external drive isn’t visible.

I’ve also tried Inject drivers into Wim. I’ve tried several things/looked up on the internet but nothing works.


D: usually is mapped to the installed version of Windows and could not be mounted. I have seen this issue on the 2018 MacBook Air, and how it is resolved is documented in that support article:

The 2018 MacBook Air (and potentially Macs after that) have cannot load the IntelMEI driver and give a “Windows Setup could not insatll one or more boot-critical drivers. To install Windows, make sure that the drivers are valid, and restart the installation”. On the USB Flash drive, open the WinPEDriver and remove the IntelMEI folder.

You can see which drives are mapped by running diskpart in the command prompt when booted from the Flash Drive. run:


Google diskpart to find usage, but this came up for me:


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I’ll give it a try. (macbook pro mid 2015)

Thank you.

@tperfitt I’m clueless now.

What I did:

  • exFAT partition with iso-copied files & windows support files (I’ve 64GB split into 32GB exFAT/NTFS)
  • with Parrallels I pre-installed the WinPEDrivers
  • I can’t find the IMEI folder to delete?

What I can do:

  • Booting from EFI
  • Assign letters to a volume/partitions of the external USB

What I can’t do:
Select an external drive to install windows on? They don’t show up in the Setup GUI

Which steps do I take to proceed the installation?