If you mean font size in reports, then those are defined in the report definitions. In order to change font size you would have to edit the report and then change the font size for each field under then Contents tab.

If you mean display font, then there is no setting for that in DVD Profiler itself, as far as I know. You can make a change in Windows settings under System / Display / Scale & layout, but that would affect all programs.

So, the unfortunate answer is that there is probably no practical solution either way.