Retrieve the "location" tab from my docs.

You certainly have a system alias pointing to a folder that no longer exists.

Check:
-Start 'regedit' from the account that has issues (may need admin password)
-Expand HKEY_CURRENT_USER/Software/Microsoft/Windows/CurrentVersion/Explorer/Shell Folders
-Ensure that the paths for the directories Download (374DE90....), Saved Games (4C5C32FF...), Contacts (56784854...), Searches (7D1D3A04...), Links (BFB9D5E0...), Desktop, Favorites, My Music, My Pictures, My Video, Documents (Personal) point to existing folders (WARNING, I have only one computer available, I could not verify that the numbers are still the same)

Fix:
-If the data is incorrect, correct it to point to the desired directories.
-If you have also lost the image that describes this kind of folder (you shouldn't have deleted the 'desktop.ini' files), point them to a dummy folder, delete or rename the corresponding folder (if it exists) in c:\user\_your_account_ (WARNING, safely copy the data they contain) and then, on the properties of the folder in the location tab, click 'Restore Default'. Windows will ask to create the directory (answer yes) with the corresponding 'desktop.ini'. Put your data back in the directory, delete the dummy folder you created for the manipulation
-IT IS NECESSARY to reboot.

1- The location tab is found in the shortcut...
You need to go through the start menu...

and not in the folder itself.

2- You just had to change the letter and click on validate (but you only like the letter so everything went to the root of D:

You will need to sort everything manually after redefining the default locations of your shortcuts.
--
Why make it simple when you can make it complicated?

You can tell Windows to set your personal documents to default on D:
It's simple:

Start
Click on your session name at the top.

Then, right-click on all the folders
Properties
When you see the "Location" tab in Properties,
you can change it there. Personally, I recommend just changing the drive letter:
which will give:
D:/user/username/my documents

Do this for the folders.

Also, when you validate, it will immediately copy the content of the said folders to D:/user/username.

Here are the folders you can move via their properties:

D:\Users\**********\Desktop (desktop)
D:\Users\**********\Contacts
D:\Users\**********\Documents (my documents)
D:\Users\**********\Favorites (favorites)
D:\Users\**********\Links (links)
D:\Users\**********\Music (my music)
D:\Users\**********\Pictures (my pictures)
D:\Users\**********\Videos (my videos)
D:\Users\**********\Saved Games (saved games)
D:\Users\**********\Searches (searches)
D:\Users\**********\Downloads (downloads)
--
Why do it simply when we can make it complicated?

You start
the name of your session
then right-click on all the folders mentioned...
and properties, they must have the location tab.

--
why do it simply when you can do it complicated?

Same problem on Windows 8 ...
I just accidentally deleted my "My Documents" folder ... and even after restoring, the folder came back, its contents too, but I no longer have the "Location" tab in the properties ... so I can no longer redefine the position of "My Documents" in Windows and all my apps can no longer find their little ... it's the m ...

Well, after some research and attempts... I restored Windows... and had to reinstall everything I did since this morning... (I had just done it because I switched to the Release Preview which deleted everything from the previous version of 8)

However, unlike you, the restore worked well for me (I remind you that I am on Windows 8... which may explain things...)

And for a little explanation, I pretty much messed up in the same way you did... trying to change the location of my documents from D:\my docs to C:\users\elloco\my docs... I forgot the last folder... so I validated the location c:\users\elloco... and Windows didn't like that too much... a user account folder trying to become a documents folder... and then the "location" tab disappeared... just like for you and your D: drive

raaaa....

What a hassle! We'll never get the answer!