So, the warranty passed for the service on my Optiplex 3020.

Someone in the house destroyed the harddisk that was in it. It now fails to boot. I've taken it out, it's formatted by some beginner cousin that tried fixing it for me when I wasn't home.

I intend to put a new SSD in it and install Win10 Pro x64 fresh on it.

I only have the Service tag on the Optiplex, but NOT a Win10 iso or Dell disk or product keys for W10 Pro anywhere.

It used to run W10 Pro x64.

How do I best clean install Win 10 Pro x64 on this machine? Will it automatically see it's installed on the same machine (through BIOS) and make it validate by MicroSoft ?