at the top of your computer screen should be File, Edit View on to Help and on the right a - sign, a box and an X. click the box to Open Menu. that enlarges your screen or makes it smaller.
otherwise i use the four stack or dashes--- in the right upper corner of the forum screen-that is probably what you want to enlarge the forum page. look in there for percentages and click Zoom to get what you need. good luck.