Thank you for replying to my query and for providing me with the link to try and solve the problem.
Having looked at the steps that I take, I can see that they refer to the login screen which is something that I don’t use the password for as I’ve turned this off in Security and Privacy. I daren’t turn it back on just in case it locks me out of the Mac altogether.
There was one solution to the problem which I tried which was to get into the boot screen. However, I’m using a Windows QUERTY keyboard so I had to improvise by substituting the Command key on an Apple keyboard for the CTRL key on mine.
This didn’t seem to work so is it something that I’m doing wrong or do I have the wrong keyboard to perform this task?
I’m reluctant to buy a new Mac keyboard simply to boot into the boot screen but if that is my only option then I suppose I’ll have to.
The question is, is it my only option?
Thank you in advance for any help and advice that you can provide.