If you're using Windows 7, usually everything defaults to the Library. If you go to a particular library, there's a "link" on top for managing folders. Add the folder in D:\ you want that Library to point to, set it as the default save location, then remove the other folders. Since everything usually defaults to the library, it'll default to the folder you pointed to in D:\
Alternatively, but it may be too late in the game, you could move your entire Users folder using robocopy to D:\, then make a symlink in C:\ called Users that points to D:\Users. And I say may be too late because this has more chance of success the earlier you do it after a fresh install. But if you want to try:
http://lifehacker.com/5467758/move-the- ... -windows-7