EXPLANATION
The default data source (ODBC) uses the 64Bit instance of
Microsoft's 32Bit ODBC connector running in the 64Bit memory space.
Microsoft's default Office installation includes the 32Bit version by
default for the highest compatibility with other applications. So, to
use ODBC connections with a default installation of Microsoft's Office
products, you must use the instance of the ODBCAD32 application that
runs in the 32Bit address space that resides in the C:\Windows\SysWOW64
directory.
This is counter intuitive when you look at the directory, one would
logically assume that the SysWOW64 directory would be for 64Bit
applications but, this is not the case: "In
computing on
Microsoft platforms,
WoW64 (
Windows 32-bit
on
Windows
64-bit) is a subsystem of the
Windows operating system capable of running
32-bit applications that is included on all
64-bit versions of Windows—including
Windows XP Professional x64 Edition,
IA-64 and
x64 versions of
Windows Server 2003, as well as 64-bit versions of
Windows Vista,
Windows Server 2008,
Windows 7,
Windows 8,
Windows Server 2012,
Windows 8.1 and
Windows 10. In
Windows Server 2008 R2 Server Core,
it is an optional component. WoW64 aims to take care of many of the
differences between 32-bit Windows and 64-bit Windows, particularly
involving structural changes to Windows itself." --
https://en.wikipedia.org/wiki/WoW64
https://support.microsoft.com/en-us/help/2721825/unable-to-create-dsn-for-microsoft-office-system-dr...