Once the downloaded file/programme has been setup/installed on your computer, can you then delete the file you have downloaded? Does it take room up on your PC hardrive unnecessarily? And finally.. can you dupicate installing the same programme or does Windows stop you doing this? thanks....
One thing you may like to consider. By downloading programs onto the desktop, it'll either get cluttered up or you'll have to delete them, unless, as the previous member said you save them on a CD. What you could do is make a new folder called whatever you like, or for example "Downloaded Programs" and once installed, copy and paste it to that file. That way you'll always have a copy to reinstall it if necessary. Once done you can safely delete the one on the Desktop.