AcuXDBC 64-bit driver was installed because the PC is 64-bit. However, when using Microsoft Excel the DSN which was set up is not listed.
While the PC hardware is 64-bit and the operating system is 64-bit, the Microsoft Office installed on it was the 32-bit version. Installing the 32-bit AcuXDBC driver will resolve the problem.
The determination of whether to install 32-bit or 64-bit is based on the bitness of the application which will be accessing the AcuXDBC driver, and NOT on the bitness of the operating system. A 64-bit operating system can host 64-bit or 32-bit applications. So first determine the bitness of the front-end application which will be used, then install that version of AcuXDBC.