Hard to follow your explanation, but....
I doubt if Vista was ever on D. The D partition was presumably a partition from which you could restore Vista to C.
It looks like you may have installed Windows 7 to what used to be D, thereby overwriting your previously available recovery partition?
And did not touch C, where Vista was originally installed?
Or I may be confused entirely about what you have done or what you originally had.
Can you post a screen shot of your Disk Management as it now exists?