Apologies in advance. Don't consider myself a beginner but yet completely stuck here... I have an SD card on my PI 3 nicely setup with all the server services and databases I need and now before progressing the project, want to create a clone for obvious reasons.
The SD card I started with, was a pre-imaged one I ordered with the PI that already had the PI OS on it.
Using windows, I used Win32Disk Imager, although my source card came up with around 4 partitions. At least one was readable and the rest were not (boot partitions, plus other unreadable partitions etc) but basically added an E: F: G: H: etc to my list of volumes on MyPC.
I created an image using the readable partition. But when writing it back to another blank generic SD card of the same size, it failed and then that card became unusable (I spent two months trying everything online to blank the destination card to try again, to no avail).
My understanding is that no matter what drive letter you select on the source SD card, Win32 DI is supposed to clone the card including volumes and partitions. But clearly something didn't work. I put it down to the alternate brand of the destination SD (although it was a class 10 Samsung item that matched the source SD brand and model number).
I've now bought 2 Raspberry PI branded SD cards (the black ones with the PI logo on them 16 GBs) online so I know I have 'good' SD cards.
Can't progress my project until I can backup and restore... Would be very very grateful for a full proof method of backing up and restoring, especially dealing with the multiple drive letters my source SD cards brings up (which are rarely mentioned) and which to select and what cards to use. Money isn't an object (to a point), but the smallest hardware duplicators I've seen around £139 1 to 2 card duplicators, reviews imply they fail after a few months despite doing the job initially for most users (but there only seem to be one or two Chinese brands available with the same issues).