I've searched the whole Internet for a solution to this problem but failed to find a solution.

Somehow an operating system upgrade was interrupted.

Now it’s stuck in an endless loop, best way to explain is to show a photo of the screen.

tapping OK just sends it in a loop.

I've tried to boot from various different media, I've removed the main and BIOS batteries and left for 4 days, but nothing helps, it ******### machine returns to that screen all the time.

I did think I could remove the hard disc and format it then install from USB media, but the connections on the disc a a mini version of SATA. So that was the end of that option.

Anyone got any suggestions please ?