In the "settings" folder is a file named "login.cfg" which contains the login information. It is a plain text file so you can open it with Notepad, it you like, or copy it to the new "settings" folder.
By the way, the DX9 version of the game may have problems if the computer is not kept very, very clean due to how DirectX 9 uses twice the resources of DirectX 11. Just FYI.