I recently ran into a problem with a new 64bit Windows 7 machine where needed a 32bit based ODBC connection modified for a 3rd party application. When I went to the typical location to modify the new ODBC connection in Control PanelAdmin Tools, the ODBC that was automatically created with the 3rd application installation was not listed. Here is a handy trick that enables you to view, edit or create a 32bit ODBC connection on a 64bit Operating System.
To bring up the 32bit ODBC settings page, browse to the following location and create or modify the connection as needed.
C:WindowsSysWOW64 and open up odbccad32.exe