Just three additions to mason's excellent reply:
If your computer has Intel graphics integrated to the processor, you can use
that instead of the video card; it would work much better (but AMD video
cards usually come with AMD processors...);
You can install the driver for the printer (and youtube-viewer) in the live
session to test whether that is working; no need to install Trisquel to test
it;
There are other solution to download/play videos from YouTube and more:
https://trisquel.info/en/wiki/play-videos-without-using-flash (I personally
use ViewTube and ViewTube+).
