I have searched a little Windows program to make a Disk Image from a Phone Micro SD card but couldn’t find one. Therefore I have to put the Micro-SD card into a USB card reader and plug it to a Linux Box.
To make a disk image:
dd if=/dev/sdb1 of=image.img
Now if you have a larger SD card and you want to upgrade, swap the card, and run
dd if=image.img of=/dev/sdb1
You need you use the dmesg to find out what’s the device number of your SD Card.