Help! Backup and restore the system partition

I have two partitions--C: contains Windows and installed apps; D: contains my data. I used "Create a system image" on the Backup and Restore screen to create an image on a USB drive (F:). Asked "Which drives do you want to include in the backup?", I left D: unchecked and created the required images for "System Reserved (System)" and "System (C:) (System)". Everything proceeded normally.

I tested this by attempting to restore with the aid of a System Repair Disc. All went well, until I got a screen offering me an opportunity to:

Format and re-partition disks.
Select this to delete any existing partitions and reformat all disks to match the layout of the system image.

And, of course, this is where I bailed out.

I want to restore only the C: partition, without changing D:. Is this possible?. Should I have made an image of the D: partition as well? Had I done so, could I have prevented restoring the D: image?

RolandJS: I guess your sub-text is that I might be wasting my time trying to get the built-in Backup-Restore function to work like I want it to. I could get Macrium Reflect, I suppose. But before I do, I'd like to make sure that the built-in really can't do what I need.

Thanks :)

After a little more experimentation, and I discovered the 2nd option--the one I had been looking for. It is only presented if the backup has two or more partitions (besides the small reserved partition). Option 2 reads this way:

Only restore system data
Select this to restore only the drives from your backup that are required to run Windows. If you have separate data drives, they will not be restored.

By "drives", they mean partitions.

Both options work, although some of the warning messages are a bit scarry.

Option 1: The physical drive is reformatted and all partitions in the backup set are written onto the target.

Option 2: the System partition (C: in my case) is restored, but all other partition (just D: in my case) are not. The bug here is that Option 2 is not offered if the backup set only has one partition. The moral is to backup at least two partitions, unless you mean to wipe all partitions except the System partitions.

The options are selected by check boxes, not radial buttons as one would expect. I have no idea what option 3 (both checked) and option 0 (neither checked) do--I probably never will know, unless I can't think of some better way to spend a weekend morning.