The option to name an application as the default viewer on a computer for supported file types is a convenience feature of the Windows operating system. This enables the user to just click on a file in the directory to open the file in the default viewer, without need to first open the viewer application and load the file to the viewer. For files for which the TatukGIS Viewer or Editor is associated as the default viewer, the TatukGIS logo appears by the file name. Appearance of the TatukGIS logo does not change the file in any way.
During the first installation of the Editor or Viewer, the user selects which extensions to associate with the TatukGIS product as the default viewer. There are two ways to later disassociate a file type or deactivate the default Viewer/Editor status.
Easy way:
Go to the Tools / Options menu item and choose the Files tab. Unselect the file extensions you do not wish to be associated with TatukGIS Editor/Viewer. It will still be possible to open the files in the TatukGIS program using the File / Open menu or by dragging files into Viewer/Editor window, but no longer possible to launch the Editor/Viewer with an associated file by just clicking on the file. Also, uninstalling the Editor/Viewer program removes all associations.
Hard Way:
Localize ttkEDT.exe or ttkVWR.exe (first take a look at C:\Program Files\TatukGIS\Editor and C:\Program Files\TatukGIS\Viewer) and run, respectively, from the command prompt:
ttkEDT.exe /u
or
ttkVWR.exe /u