Let's pretend you have that earlier correct full image of the original full of data partition D.
Before we do anything further, I would highly recommend you create a usb or dvd boot partition manager utility.
With this utility, look very carefully at your hard-drive. What you KNOW to be drive C [partition C], label that C-Drive.
What you KNOW to be drive D [partition D], label that D-Drive.
There is no need to do anything else with that partition utility.
What we have done: going forward, from now on, regardless of the drive letter dance/shuffle/pokerplaying etc. done by any backup/restore utility, you know which is drive C [partition C] and you know which is drive D [partition D].