This software is a shareware. You will be able to download and test Planets Space Moons Screensavers during a certain period of time, then, if it does what you need, you will have to acquire the full version. The trial version available for download on www.softandco.com has a size of 10364 KBytes. For additional information and support request, please contact directly Planets Space Moons Screensavers publisher.