They both install the same version of the program. The .msi file uses the Microsoft Windows installer, a program that is available on Windows 2000 and later operating systems. It may also be available in computers running older version of Windows if you have downloaded and installed programs from Microsoft. The .zip file contains a setup file that uses another installer, and is smaller of the two files.

The network administrators at many places of work, prefer to use .msi files as they fit into the way software is distributed and installed in their organization. Other organizations prohibit download of .zip or .exe files, but will allow .msi files, as such files contain information about the programs being installed that can be read without installing the program.

If you have a newer computer, the choice is your convenience. If you are running an older Windows operating system, it is possible that you do not have the Windows installer, and should probably use the .zip version. In any case, if you are downloading to install an updated version of ndxCards, please download and install using the same type of file you used previously. Also remember to backup your ndxCards data, as occasionally an install will overwrite your data and you may lose it.