What is the earliest version of linux/ubuntu that this works with?

[InquilineKea]

Trying to restore a PC from 2009 (Asus G51vx). It is x64

[SomeCrazyGuy]

You can use the live iso from 2022, modern linux runs on very old hardware. But I would recommend taking out the hard drive from the old computer to recover it on a system with hddsuperclone already setup. I would also recommend testing hddsuperclone with a known working source and target drive to get used to the workflow and expected operation before trying to recover a failing drive. You may only have one shot at recovering the data so it would be wise to have some experience first.