I don't know of a way to make PAF display larger fonts than those that are built in. I heard once of other fonts and sizes being used by people running PAF on Linux (under W.I.N.E.), but I don't know how they do it.
Yesterday we bought a new computer for my wife and I found the menus in the programs were so miniscule that they could be read only with the greatest effort. By changing settings in the software I could make text larger, but not the menus. Then I discovered that Windows8 was using the monitor's highest possible resolution. Changing the resolution to 1024x768 (like her old computer) made the menus much larger and easily readable.
Changing the Windows screen resolution on your computer would have the same result, but would make other things larger too. I don't know whether this would work for you.