To manage a data source that connects to a 32-bit driver under 64-bit platform, use c:\windows\sysWOW64\odbcad32.exe.
To manage a data source that connects to a 64-bit driver, use c:\windows\system32\odbcad32.exe.
Taken from: http://msdn.microsoft.com/en-us/library/windows/desktop/ms712362(v=vs.85).aspx
Idit. 🙂