"This software cannot be installed on this computer" OS install error
I picked up a mid-2007 iMac with El Captain installed and working (more or less.) It did not have a password set for the user, and there was no Apple ID signed in. It was having some issues, so I decided to re-install the OS. I booted into Recovery Mode and erased the drive, and then proceeded to try re-installing the OS through the utility. After signing in with my Apple ID, it displayed an error message reading “This item is temporarily unavailable. Please try again later.”
The iMac also came with its original OS X install discs (version 10.4.8,) so I figured that I could boot from the install disc and re-install the original OS. Upon booting from the disc, the installation utility displays a "This software cannot be installed on this computer" error. I’ve tried resetting the date to 1-day after 10.4.8’s release date (9/30/2006) to bypass the version signing roadblock, but to now avail. Even after doing that, the same error is displayed.
I tried following this solution, however, when I try to create a new partition, I get a “Partition failed with this error: Input/output error.” Interestingly enough, the installed drive is a 1TB drive but the DU is reading it as a 7.3TB Drive. The DU also says that the drive is verified. Under the “First Aid” tab for the drive, there are no drives visible in the list.
From what I've read, the input/output error usually indicates that the drive has failed. I don’t know how the drive suddenly failed, as it was working fine earlier today and booted into Recovery Mode multiple times with no issues. Perhaps erasing the drive in Recovery Mode somehow damaged it? Which would defeat the purpose of Recovery Mode.
Now, when I start the computer and try to boot into Recovery Mode with Command+R, nothing happens and the folder icon with a question mark just flashes on the screen.
Any ideas? Any help would be greatly appreciated!
EDIT: Updated device from 21.5” model to 20” model.