Creating a system ODBC data source on 64-bit Windows   64-bit versions of Windows maintain two sets of system data sources: one for 64-bit applications and one for 32-bit applications. To create a system data source that is accessible to 32-bit applications, you must run the 32-bit ODBC Data Source Administrator (located in the WINDOWS\System32 folder). To avoid connection problems, set up your 32-bit system data source exactly like your 64-bit system data source.

Creating a user ODBC data source on 64-bit Windows   64-bit versions of Windows maintain one set of user data sources. You can use either the 32-bit or the 64-bit version of the ODBC Data Source Administrator to create a user data source. This data source can be used both by 64-bit and 32-bit applications as long as the matching driver is installed. For example, this user data source can be used by a 32-bit application as long as the 32-bit ODBC driver, dbodbc12.dll, is installed in %SQLANY12%. It can also be used by a 64-bit application as long as the 64-bit ODBC driver, dbodbc12.dll, is installed in %SQLANY12%.