Coaching Computer

I was in some sort of computer lab, trying to introduce Computer to my Uncle. He is not computer literate so it seems that he is picking up quite well. It seems that I am using linux of some sort and let him wathing movie and browsing couple of news.
I was distracted doing something and he need me to change some of the setting so I had to use keyboard to go through all the opened program which seems to be limitless before I can get to the settings.