Creating a system data source on 64-bit Windows   System data sources are available to all users of the computer system and to Windows services. 64-bit versions of Windows maintain two sets of system data sources in the Windows Registry: one for 64-bit client applications and one for 32-bit client 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 %windir%\syswow64 folder). To avoid connection problems, it is recommended that you create both 64-bit and 32-bit system data sources and ensure that they are configured identically.

Creating a user data source on 64-bit Windows   User data source definitions are stored in the part of the Windows Registry containing settings for the user currently logged on to the system. 64-bit versions of Windows maintain one set of user data sources in the Windows Registry for each user of the computer. 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 by both 64-bit and 32-bit client applications as long as the matching ODBC driver is installed.