Windows 7 has recovery(d:) as the default file which contains windows.old (Vista), windows, program files, library, and users file.
The recovery(d:) drive has space problems. Would I have to reinstall Windows 7?
Windows.old does not belong there. When you are done with it, just delete it. The other files you mentioned are probably part of the recovery partition. If you post a picture of D:, we would know better.