Hi
My two cents worth, if you installed Windows in your C:\Windows directory it would have replaced your original Widows installation and move the old file data to a Windows.old file.
Your D:\ would have been unaffected and nothing would have been moved there.
If you installed the new Windows 7 installation to your D:\ drive, (I'm pretty sure this is what you did) then it over wrote the existing data on the drive. Because there was no operating system on the drive I don't think it will create the Windows.old file.
And, your D:\ drive will now be your C:\ drive when you log into Windows and your C:\ drive will be your D:\ drive.
If you did that, then you should have 2 working Windows installations and you should be asked which one you want to log into when you boot your computer. I don't know why that isn't happening.
If after booting to your new Windows installation, you look in Windows Explorer see that your old Windows installation still there, on dirve D:\ then you probably installed over your data and it's most likely unrecoverable.
If your data is anyplace it's on what is now your C:\ drive, because it was your D:\ drive before you installed Windows on it.
I know this is confusing.
Mike
Well now that I see the screen shot I'm more confused, there is a Windows Old folder but no installed operating system on D:\.
I don't know how that could happen?
I'm pretty sure you installed on D:\ there isn't any reason that it would have done anything to D:\ or put the Widows Old folder there unless you did, but I don't know what happened to the previous Windows installation?
I'm still pretty sure that what is your C:\ drive now used to be your D:\ drive.
Maybe it works different because both dives are partitions on the same disk?
Anyway if you are going to try and use Recova I would be sure and look for your files on the C:\ partition too! It's possible that some of you files could be recovered but I don't know what the odds are.