Update :
Hopefully this will help clarify the issue - courtesy of IBM (IBM ODBC driver could not be loaded due to system error code 193 - United States)
On 64-bit Windows, there are two versions of the Microsoft ODBC Administrator tool. Typically, you go to Start --> Administrative Tools --> Data Sources (ODBC) to create ODBC connections. This calls the program %WINDIR%\System32\odbcad32.exe to create a 64-bit ODBC connection. However, this program will not create 32-bit ODBC connections.
The ODBC gateway requires a 32-bit ODBC connection. Use the 32-bit version of the Microsoft ODBC Administrator tool located in %systemdrive%\Windows\SysWoW64\odbcad32.exe to create the ODBC Data Source.