I don't think I can get into the BIOS - I only know of hitting del or going into setup after turning on power for a boot which I am unable to do at the moment. If there is another way it is not something I know how to do.
I had previously spoken with Acer, a few days ago before starting this post, who suggested doing something called a static discharge which did not work either.
I will have a go at using the drive from the other acer (something I had considered earlier) after I have ensured my backup procedure is working. Not overly optimistic that the situation will improve, but who knows, worth a try.