I have a MacBook Air 7.2 early 2015: i5 2.4GHz, 8Gb DDR3, 121Gb SSD which is completely empty and I want to reinstall macOS on it. I booted my USB key under Macos Sierra from a dmg file with TransMac, but it doesn't appear as an option in Startup Manager.

After checking the key in Ubuntu, I finds that the EFI partition is empty (0 bytes out of 230 mb), which I think is the cause.

The internet resolution offers me as a reinstallation macOS Monterey, and it seems impossible to me with the quality of connection that I have.

How can I get the Sierra installer to boot from a USB drive?


1 Answer 1


There are ready exists the question How can I download an older version of OS X/macOS? which is similar to your question. However, since you used TransMac, I assume you are trying to create a bootable Sierra installer from a Windows machine. In this case, there is this answer which is for El Captain, but should also work for Sierra. Where necessary you would need to substitute Sierra for El Capitan in the instructions.

  • 1
    The USB key has indeed been booted under macOS Sierra and I was able to reinstall my Mac! Thanks very much @David Anderson Commented Jan 24, 2023 at 13:14
  • If you feel my answer solved your problem, then please accept the answer. This will put a green check mark next to my answer. Others will then know a solution has been found. Commented Jan 24, 2023 at 13:20

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