Beginner's installation problem in linux

[chrisnd]

Still concerned why isn't this do-able in Ubuntu software downloader?

Hi Chris,

what do you mean with that? Is there a special mechanism in Ubuntu to distribute software?

Yes indeed.  Ubuntu currently installs with something called 'Ubuntu Software' - which is basically analogous to 'Google Play' on Android phones etc.
If you try and install anything that isn't recognised as an 'approved'* app then all sorts of dire warnings are given - hence my question, and comments, here.
HTH
C

*for want of a better word