After I exited MRF8, I restarted the M4700 and pressed the F12 key to access the M4700's BIOS Boot Options menu. Next, I used the arrow keys to find the actual Western Digital part number of the external HDD - which I was pleasantly surprised to see - and pressed ENTER.
As I mentioned in our DM, the big drive manufacturers offer a free disk copying/cloning/imaging application you can use with their products, in the case of Western Digital, it is a custom version of Acronis True Image for Windows that is customized to function if a qualifying Western Digital product is either the source or destination drive. In case the download link below is sessionized,
here is the gateway link to select your product type first, and then scroll down to the section for downloading Acronis True Image for WD.
Direct download link (737MB) to Acronis True Image for Western Digital
User Manual for Acronis True Image (Western Digital)
Disk cloning is to create an exact duplicate of a drive, all data and structures (partitions, boot sectors). It results in an identical copy of the drive. Traditionally, this literally had to be drives of identical capacity but for many years now the software can negotiate some differences between the two drive capacities.
If I gave you the impression that you could BOOT directly from a disk FILE image or cloned disk across a USB external device, I apologize for the misunderstanding. I had troubles understanding what it was exactly that you wanted to do, it seemed you waffled some bit between a straight-forward cloning/duplication of one drive to another drive and saving a disk image to file. Here is my message:
Macrium Free does all of that. Only things I think are limitations are imaging or restoring over a network, using virtual disk images, and restoring to dissimilar hardware.
I understood you just want to create a backup or image of the M4700 as shipped, not a recurring backup solution. This can be done by acquiring an extra drive, cloning the M4700 to it either directly or from a disk image file. Then you can put the duplicate disk in a drawer for safe keeping. Or you can image the entire disk to a file, on USB drive or even DVD, create bootable rescue media, and put them all away for safe keeping.
Additionally, you can open/load/mount the image FILES using the Macrium program when it is installed on a PC, browse the contents of the image, extract or copy any files contained, but not BOOT from the image files. Windows does not support that, you'd need a special boot loader app or process that would handle/open the Macrium image files, which are NOT industry standard image files they are only readable by the Macrium executable.
OH and BTW, if you cloned the M4700 drive to the external USB drive, it would boot if you then REMOVE the drive from the external enclosure and install it in place of (or in addition to) the M4700 internal drive. But since the M4700 is no longer operational, I'm unsure what it is that you want to do. You already have now two copies of the M4700 drive; the M4700's internal drive and another in the external USB enclosure.