I just received a MacBook Air with OS High Sierra. While it was updating, I turned it off because 2 hours had passed for a message that said “. . . remaining 2 minutes.” Now it will not reboot even with Command-R or Shift key hold down after power on.
iPad Air 2 Wi-Fi, iOS 10.2.1
Perhaps an authorized Apple service provider could help you
re-install a suitable macOS; or a Genius (apple store) may be
helpful. Either of these should have reliable &/or faster internet.
If you were relying on wi-fi, your most recent upgrade to later
macOS may take up to four or six hours; plus more for extras.
There are additional 'recovery' key shortcuts to get optional
methods or system choices from the article macOS Recovery.
• About macOS Recovery - Apple Support
• How to reinstall macOS - Apple Support
Choices include the ability to fully erase a system, too; but if you
do not have a backup and/or Time Machine copy of your macOS
avoid erasure; however if you take the Mac to an authorized service
they may have to erase its content. It's always advisable to backup.
..Without one, your personal created content would likely be lost..
Good luck & happy trails! 🙂
Maybe you should schedule an appointment at an Apple Store to have a Mac Genius look at it.
The purchaser didn’t buy Apple Care, so I was trying to avoid paying for the repair and do it myself. But, if no one can help me, then, that will be my last resort.
Turned off while updating. Now it will not reboot. Command-R and Shift hold down do not work to reboot.
