This text is missing some spaces, please add them: InthecasethatyourAT3filedoesn'topen,itishighlylikelythatyoudonothavethecorrectsoftwareapplicationinstalledonyourPCtovieworeditAT3fileextensions.
In the case that your AT3 file doesn't open, it is highly likely that you do not have the correct software application installed on your PC to view or edit AT3 file extensions.