Cartes du Ciel is free software released under the terms of the
GNU General Public License
It is possible to install the Cartes du Ciel-SkyChart version 3.0 over a full Windows version 2.76 in the same directory, and run the Cartes du Ciel-SkyChart 2.76 version apart from the 3.0 version. But you can also install the 3.0 version of Cartes du Ciel-SkyChart only.
Run the installer file
skychart_3.xxxxx.exe, to install Cartes du Ciel-SkyChart in your prefered directory
(i.e. C:\Program Files\Ciel)
At any time you can start the version 3 with
skychart.exe, or the 2.76 version with
Video recording require the ffmpeg software.
You can get a ready to install version for Windows from a number of places:
You can install the files anywhere you want, but be sure to set the location of ffmpeg.exe in the menu Setup / Date-Time / Animation.