backup memorycard rpi3b with domoticz

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Hi, i like to backup the memorycard of my raspberrt pi3b with debian stretch (full) and domoticz. ( i used noobs)

I have sd imager to make an image of the memorycard. I tried it with a simple card and it works fine!
But when i tried to make a backup of my debianstretch/domoticz

i have four disks to choose from (i use sd imager within win10).
disk f: not accessible
disk g: accessible, files visible
disk h: accessible, files visible
disk j not accesible

when i remove the memorycard all four disk are gone, so they belong to te memorycard.
Which drive do i have to choose to make a working copy of my entire system ?
I can choose F: although it is not accesible by win10 (win10 wants to format it)