Problem installing High Sierra

Sounds like your Time Machine backup has introduced something that is causing the install process to report an error.

You can use internet recovery to reinstall the original OS, probably Sierra, About macOS Recovery - Apple Support

Once restored to shipping condition try the upgrade to High Sierra. You can then use Time Machine to restore your files/ photos/ movies, documents etc but don't restore any Systems and/ or settings files as that may introduce the problem again.

Flakesobran wrote:

I had a 21.5” iMac that I bought in september that I voided the warranty by adding more ram and accidentally broke the webcam. I tried to upgrade to high sierra and because the camera was broken high sierra wouldn’t load up. The process claimed that that there were problem and as a result High Sierra couldn’t install.

Fine.

Two days ago I bought a brand new 27” iMac. I used time machine to reinstall my system. And was in the process of upgrading to High Sierra. The process still claims that there are hardware issues and because of this the new system cannot install.

Those are two different problems. The first one can probably be fixed by replacing the FaceTime camera assembly or whatever broken parts are associated with it, should you ever be so inclined to do that.

You won't be able to "restore everything" from the older one's Time Machine backup, but you can use Setup Assistant to migrate its content to your new iMac. Since you probably now have a brand new iMac that won't boot, use macOS Recovery to install High Sierra. Then, when asked if you want to transfer information from a Time Machine backup, choose that option.

Or, just Contact Support. 90 days of complimentary telephone or chat support is included with its purchase price. They will be able to talk you through transferring information from the older one's Time Machine backup.

Shift-Option-Command-R will install the version of OS your mac shipped with.

How to reinstall macOS - Apple Support

You should install High Sierra after erasing your HDD and then import your apps and data from the backup.

Yup. The install failed. Froze my machine. brought to authorized apple dealer. $100 to fix. Who at apple is going to pay th bill?? (ha ha).