Problem: 

Installation of the  64bit AccessDatabaseEngine on a computer that is installed with 32bit MS Office is not supported by Microsoft.

Symptom:

 The following error occurs when attempting to perform a normal installation of the 64bit AccessDatabaseEngine

Solution:

The 64bit  AccessDatabaseEngine_x64 can be installed from  the  command line with the \passive argument, following the steps below:

1. Download the zip file from the link below in the Downloads folder on your computer, unzip it, and change the extension of the file from txt to exe

https://datasci.box.com/s/khjh3coa2usqcohyk78sndyj6x1kvq0e

2. Open the Command Prompt by typing cmd in the Windows search box under the Windows Start menu and select the Command Prompt App
3. Type the file path and file name of the 64-bit Access Database Engine install file, followed by a space and /passive (see screenshot below). 

This should complete the installation of the AccessDatabaseEngine_x64, without error messages.

4. Type regedit in the Windows search box under Windows Start menu to open the Registry editor and select Registry Editor App
5. In the Register Editor window navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\14.0\Common\FilesPaths 
and delete the mso.dll file

Note:
If the mso.dll registry value is not deleted, every time when an Office application is opened, Reconfiguring message will pop up.