My MacBook Air comes originally with El Capitan.

I call to Apple Support because I want install a clean macOS Sierra, and they told me Hold Command+R, delete the Hard Disk, and next Select Reinstall.

By default the connection was Wifi. The problem, this connection is very slowly, I haven't option to select my thunderbold LAN connection, instead of Wifi.

The Wifi for me its vey problematic, and I need to reboot. Then appears world globe... After I delete my HD again, but Appears El Capitan.

The problem this methods needs 10 hours over a problematic wifi.

I think that I need to install El Capitan later upgrade to Sierra Later again repeat the procedure (delete HD & Format) to perform a Clean installation of macOS Sierra.

Is there a Quickly method?

Is recommended Alt over Command+R?

How can I to select Thunderbolt LAN connection by default to install macOS?

Note: I haven't runnable macOS now in My MacBook!

NOTE: I have a macOS Sierra installer on USB External Hard Disk (Original & Modified), but I don't know how install directly from USB.

  • You don't "select" your LAN connection. Just disable Wifi, and plug the computer into the LAN, and things should work. Jun 15, 2017 at 23:39

1 Answer 1


You can do a clean install easily:

  1. Attach the USB installer
  2. Reboot holding the Option key
  3. Hold on until you see the "install Mac OS Sierra" volume
  4. Choose "Disk utility" in the Mac OS utilities screen
  5. Select you HD and erase it
  6. Format it in hfs+, usually with the name "Macintosh HD"
  7. And finally choose "Install Mac OS"

You may want to backup your data first.

  • I haven't USB exclusively with the macOS installer, I have my entire Backup 1TByte with the original installer inside multiple folders...
    – joseluisbz
    Jun 15, 2017 at 19:54
  • Then I suggest you find a running Mac to create a USB installer, it's the easiest solution. 'sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/USB --applicationpath /Applications/Install\ macOS\ Sierra.app --nointeraction' Jun 15, 2017 at 20:07

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