Windows provides for the linking of files with particular extensions to icon bitmaps provided with the application.

Matrix comes with icons which may be linked to its file types so that these files may be easily identified in desktop displays and file dialogs.

These icons are stored in the folder called Icons in the Matrix folder

Windows can be instructed to attach certain icons to Matrix file types by opening the View | Options menu item and selecting the File Types tab.

Further details on this process is available in your Windows help documentation.