Ctrl+0 (that is a zero) should reset it, or via the menus: View -> Zoom -> Reset.

The first 2 steps of View & Zoom work fine but, when I select Default, the screen returns to the original small screen size - What I need is to know how to reset the Default screen size.

Okay, I don't know how to reset the default size. However, you can go to view, zoom, and just choose zoom in!

Step 1: To make the screen a bigger font size by default, i tried this and it worked for me: Tools, Options, Content Fonts and Colors: change your lower number to a larger number font size for example 20, click on advanced button to the right of the 20, change numbers in the three places to 20, click ok, click ok. Bonus Step 2: while you are playing with default screen font sizes, life will also become easier if you also add the plus and minus zoom buttons to your toolbar: View, Toolbars, Customize, and drag any toolbar buttons you like into the toolbar. By having the + and - buttons you can adjust for size readability of your browser view with just one mouse click or two. windows xp, firefox 4.0

Thanks BB for leading me in the right direction. Along with font size you can also change the font. Mine was set to Times New Roman as a result of some previous tinkering. If did not render well and did not respond to a Win7 restore. In Firefox options I changed it to System font and all is clear. What is the default font for FF? Cheers, GC