I think I understand that now. My file-by-file backup is a clone copy, complete with all partitions, so I thought it would be bootable, but I guess not. But darn it, I would have thought it would be, it is byte-for-byte the same as the original drive. Go figure.

Anyway, a little further investigation shows me the error of my ways, I was supposed to use Macrium to make an image copy of my system drive, and then use another function of Macrium to create a bootable USB stick that contains a utility to copy my image onto my system drive.

My system drive is now clean and malware free (it will start Excel ready to type in well under one second) so it is ready to clone. I have a couple of Kingston USB 3.0 32GB flash drives on order from Amazon Mexico, they'll be here in a few days. Meanwhile, I'll re-do my clone as an image like I should have done in the first place.

Thanks, as always, Tony.

tanstaafl.