High Sierra install is frozen

Success: I resolved this exact problem. When trying to install High Sierra, my Mac was stuck the black startup screen, stalling at either 90% or 100% completion between restarts.

I managed to get High Sierra installed without losing any of my files. Here is how I did it.

Failures:

• Resetting a billion times.
• Resetting PRAM.
• Resetting CMD.
• Using Safe Mode.
• Using Recovery Mode (It would freeze upon attempting to re-install the OS, and Disk Utility couldn't detect my drive).
• Using Internet Recovery Mode (Same as above).
• Looking at Verbose startup mode -- it said "Error 13" on the drive IO.
• Talking to the "geniuses" at an Apple Bar, as well as online tech support. They suggested either formatting my drive, or even buying a new drive. They had no inclination to dig into the problem and actually figure it out and fix it.

What worked:

• I put my Mac in Target Disk mode (hold down T upon startup).
• I connected my Macbook to another Macbook using a Thunderbolt cable. The other Macbook must be running High Sierra. If you don't have a friend with a Macbook, you might be sh*t out of luck.
• I made a backup of my files, in case things went poorly. My Macbook appeared as a drive on my friend's High Sierra computer, but dragging files over in Finder resulted in an error. I had to use Terminal and "cp" my files over.
• I opened Disk Utility on my friend's computer, and here are the steps I took:
  • View -> Show All Devices
  • My Macbook showed up, along with various "Container disks".
  • I ran First Aid/Repair on all of the various things I saw. Some of them threw errors and refused to repair, but that seems to have been okay.
• I then created a bootable USB installer as per How to create a bootable installer for macOS - Apple Support using my friend's computer.
• I ejected my Mac, disconnected it from the other computer, and booted my Mac onto the USB booter. I ran the installer from the USB stick, and it succeeded! After it completed, High Sierra booted up, and all of my files were present, unharmed.

This was a huge headache for me, and I hope that this writeup helps save your files. Don't necessarily listen to the Apple "geniuses" who say that a format is necessary.

Try a hard reset: press the on/off button until the system shuts down (± 5 seconds) and power back on. The process should continue where it was left before the boot, but in my recollection about installing High Sierra it now finishes the install swiftly.

I have this problem and phoned Apple support and the outcome was that my MacBook Pro of 2011 is too old for this update, and to get it cleared and restart I had to delete everything and re-install. Luckily I have time Machine backup, but it took ages and cost me a day's work.

Calling Apple support would be best

https://support.apple.com

Thanks. I was stuck at 95%. I shut down my mid 2011 iMac and then turned it back on. The progress bar was still there. I waited a few minutes and to my amazethe update completed quickly. I now have high Sierra. Wonderful.

I had the same frozen problem (17 hours) as the original question. Read your replies. Did a boot into safe mode: and got a gray screen of hash lines; did another safe boot and got a dim grey screen with lesser hash lines with 3 horizontally spaced login pictures and password blocks. Did one more safe boot and got a nice login screen - except for an errant upper right corner 3 inch long hashed up line. Apparently working, except every search bar press in Chrome blinks the screen. Graphics card/screen showed no prior problems. MBP 13in early 2011 OS X 10.11.6 (Comparisons to Windows ... deleted)

Good advice!

I had trouble upgrading from the latest bèta release since the App Store error'ed out every single time I tried to install the public release, probable due to the installed beta access utility, but luckily I had another Mac that was still on Sierra and was able to download High Sierra, put that on a USB Flash drive and install went smoothly from there on.

I had same problem I enabled journaled disc and hey it worked (in disc utility)

Having the same problem with my iMac mid-2011 here in Sweden.

My back up is too old as I don't want to restore from 2016.

Tried installing re-installing High Sierra from a USB but the progress bar still stops at the end and I've left it for 24hrs.

Are there any solutions?

Myself I tried everything including hard reset and nothing worked the update froze and completely screwed up my iMac for days and even made it hard to restore. I will not trust another upgrade until Apple say it's all sorted and the upgrade will now install on all their products including ones with a normal hard drive and running 10.12.6. Have read nothing from Apple so assume the issue is harder to fix then they thought.

Thanks and I fear you are right.

I've now got a 27" mac which is dark on one side, fills with visible dust and now leaves me unable to work.

I'm so lucky I have a laptop and Dropbox.

Apple is no longer a company to trust.

Apple is no longer a company to trust.

Terrible thing to say but when I saw the new upgrade I thought great clicked on install and ended up losing my iMac for two days and even had a lot of problems getting it to restore the backup. I would want a statement from Apple to say that High Sierra is now safe to install before I try again. Even then I would wait until I could if it went wrong again lose my iMac for a day or two.

My OS 10.12.6

8 Memory

loads of space on hard drive (normal hard drive 500GB SATA Disk)

iMac mid 2010

But last time if froze and screwed up my iMac I restored and tried again this time it hung for hours again tried everything including hard reboot and unplugging and plugging in again leaving it for hours it still hung and getting the restore screen was a real pain.

So as the update been fixed to work I have read nothing to say it will now work on my spec iMac

I'm glad you're back up and running! :-)

Wish I could say the same. Still stuck here and my mac has loads of space too.

I'm thinking of joining Apple Developers and downloading 10.13.3 beta.

Would that make things worse or possibly solve it?