Restore disk image to a fresh Windows 10 installation

Many thanks. It's now 22:00 hrs local and I'm about to turn in. Will try suggestions tomorrow.

Thanks everybody!

I'm not a hardware person and maybe my ideas won't make sense, but in case they might this is what I'm thinking.

On the issue of "current version of Windows is in an unsupported directory", what is your current version?

Even though your data is on an external HDD, create another set of your data on a USB flash drive in case it becomes necessary to repeat the method to store your data on the physically separate HDD.

Disconnect all external drives as mentioned. With everything out of the way, try the "Keep personal files and apps" procedure you tried before. The intent here is to determine if your apps will be saved so you will not have to re-install them.

If that works and you end up with an unallocated partition you can consider merging it with your OS partition. I did that once for a friend using mini-tool partition wizard free Best Free Partition Manager for Windows | MiniTool Partition Free if I remember correctly.
--- And if it does work, create a system image back up before moving on.

If those ideas don't work, you will have to re-install your apps.

OK everybody - masses of valuable expert advice and information. Having considered all the options I've decided to leave everything where it is. If I started storing data on F: then, if I have to reinstall Windows, I risk losing any data in that partition. I'll just use it for temporary storage of anything that is relatively unimportant.

Many, many thanks for all the help.

Ken