On a 64-bit Windows machine, you can execute both 64-bit and 32-bit applications. Many applications are available in 32-bit versions only, and running 32-bit applications on 64-bit operating systems is common.
However, in a single running process, all of the code must be either 32-bit or 64-bit. A driver must have the same bitness as the application that loads it.
When using 64-bit Windows, it is very important that you configure 32-bit drivers with the 32-bit ODBC data source administrator, and 64-bit drivers with the 64-bit ODBC Data Source Administrator. This can cause confusion, where what appears to be a perfectly configured ODBC DSN does not work because it is loading the wrong kind of driver.
On a 64-bit Windows machine, use the Control Panel to launch the 64-bit ODBC data source administrator.
To launch the 32-bit ODBC data source administrator, run the following:
Create a shortcut to the 32-bit ODBC Data Source Administrator on your Desktop or Start menu if you configure 32-bit data sources frequently.