At this stage you should support your local computer technician imho. To be honest without somehow remotely connecting or being at the computer, its very hard to diagnose these issues.
Sorry mate.
If you cannot do that, buy a new HDD (any one that is new, cheap is fine).
See if you can install OS correctly on that, if you can great. You know the original drive or sata interface is faulty.
Ensure you have the correct bios settings for the hard drives, ensure you voltages and frequencies are correct for RAM.
Keep all else default.
Install OS if you can.
else; goto 10