Hello 6 X 6,
I got as far as :- I’ve read the reply from @leroydouglas, complex! The easiest course for me seems:-
{2. Restart the Mac into Recovery Mode. To do that, select Restart from the Apple menu and hold down the Command and “R” keys (often abbreviated as CMD+R) until you see the Apple Logo or a spinning globe. You’ll be dropped into the macOS Utilities.
3. Launch Disk utility. Click-select your named boot volume. (Not the physical drive above it.) In this example, it’s called “John’s-MacBook.”
4. In the Disk Utility Edit menu, select “Convert to APFS.” (It will be dimmed if you didn’t properly select the boot volume.)
I’m preparing to follow the above instructions but being a bit hesitant I would like to check a couple of things please.
Just looking in Disk utility before going in to Recovery Mode, in the LH column I have a heading “Internal” below which is a disc icon with MHD alongside, below that another heading “Disk Images” below which is a disc icon with InstallESD alongside. When in recovery mode I am going to click on MHD, right?
If I click on that now, just to see and before being in recovery mode, convert to APFS in Edit is greyed out but presumably it will not be greyed out when in recovery mode, I hope.
You said about a Mac expert, well when Limnos joined the conversation I took him to be the Mac expert, I replied to him and was waiting for him to come back.
You told me about clicking on View in Disk Utility and that brought up some more discs, I could show you that if you tell me how to put an image in a post.
Thanks again
nebb