I have iMac A1418 with High Sierra on it. I had to erase entire Macintosh HD disk hoping to reinstall OS on a ‘clean’ drive.
Unfortunately I’m not able to accomplish this as when I select “Reinstall macOS” in macOS utilities window and when it comes to selecting a disk on which I want to install OS, I can’t select a disk (Macintosh HD is displayed) and I can’t press “Install” button since it is greyed out.
It looks like window is waiting for me to click on desired disk - but I’m not able to do this because mouse is not functional and don’t see how I can select disk with keyboard.
I would appreciate any suggestions
UPD: eventually I resolved my issue by installing High Sierra on external SDD drive and booting iMac from it - this however doesn’t answer the question raised in this post.