What happens without CDXA Reader is that your system will scan the entire file, for several minutes, and afterwards, it will display an error and announce you that the file cannot be played.
In order to avoid this nuisance, simply install this filter to your computer and enjoy your favorite movies free of troubles.
It is possible for the CDXA Reader to require a special installation process (unarchive, copy DLL and AX files to “system 32” and use “Start\Run”.
If you are unable to install the filter, we suggest you to read this small guide: How to install/uninstall DLL and AX codec files
Without this tiny piece of software of just 500KB, you will get errors when trying to open a VCD, SVCD or XCD file.