Take a look at the sentence again:
Jacques, a self-taught computer whiz, always hates going to his Introduction
to Microcomputers class the reason is that both his textbook and professor
are at least a year behind when they discuss
software and internal components.
No punctuation of any kind is necessary between behind and when. That both his textbook and professor are at least a year behind is a subordinate clause. When they discuss software and internal components is another subordinate clause. When you attach one subordinate clause to the end of a second, you seldom need punctuation.
Go back to the sentence to try again.