right click on a blank spot on the toolbar and look for the toolbar options. you may have to go into the display settings and I think it is under an advanced tab but there is a place you can change the dpi to a larger dpi that is what I did on one of my xp machines.

You might try in the internet options for Fonts, Webpage Font,,, Veranda I use it, its a larger clearified font. You can also hold down Ctrl key while rolling your mouse scroll button. It will zoom/unzoom fonts .

I also use "no squint" and it's great. You can adjust size and color of the text or the size of everything on the monitor. It will also change the colors of the background from that bright white. It really helps with eye strain.

That is the registry fix worked on 8 but according to posters who have this same problem, says it doesn't work on 8.1. I am going to play around with enlarging every thing and possibly using one of my FF apps to work on the other. I can use it the way it is, it's just one of those things that nags at me and keeps me looking for a fix. I had a problem with personalize/color (taskbar) and kept messing with it until I stumbled on a fix. My taskbar was snow white and didn't match my wallpaper, all the borders were snow white. the option shown below was missing.