I have a system drive clone made with Macrium Reflect. It is not a drive image, but a file-by-file backup of my C: drive. This copy was made onto an external removable hard drive, and is kept locked up in a fire safe along with backup copies of of my already backed-up files.

This makes me feel nice and secure, ready for anything... except (and I bet you're way ahead of me here ) my computer won't boot from a USB drive. I'm guessing that if I had to I could open the computer case, substitute my cloned drive for one of the data drives and then I could boot from the clone to copy it over my corrupted C: drive. If I had to. Is that correct?

That's not as easy a task as it might appear on the surface. To do that I have to drag my large, very heavy computer hutch away from the wall, get behind it to disconnect a lot of cables, move the UPS out of the way, and finally take out a bunch of screws on the back of the tower case to get the side panels off and get access to the hard drives.

I'm betting there is an easier way. How would I go about convincing my Windows 10 operating system to boot to an external USB drive?

tanstaafl.

So, I think you are asking how to make a bootable-from-USB copy of your Win10 installation?

I confess that I actually do have one copy of Win10 in the household, which came with my recent Dell XPS13 notebook. I installed it to an external USB SSD drive, and when I want to do Dell BIOS updates and the like, I boot/run it over USB.

I forget how I set that drive up originally, but it was probably with something found by searching for it:

https://lmgtfy.com/?q=boot+windows+10+from+usb

Possibly this:
https://www.pcmag.com/how-to/how-to-run-windows-10-from-a-usb-drive (WinToUSB)

EDIT: Yes, I used WinToUSB.

Can't boot from a file-by-file backup drive.

Disk drive must be correctly partitioned and made bootable.

Also be wary of the possibility that whatever messed up your real drive might also have messed up (or will mess up) your backup drive too. For example, a virus, or a bad power supply, or some such.

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.