What version of e-Sword did you install on the Windows 10 computer?
Starting with e-Sword 11, the font controls and font color options for e-Sword were changed as part of allowing e-Sword to use html modules.
Does the font issue you have effect all of the installed modules or just some of the installed modules?
If the font issue effects some modules but not others it might be the font the module was created with causing the issue. Some modules have specific font settings that prevent the user from changing them in e-Sword
Affects all modules, and all modules are adjustable. I installed the latest version of E-sword. Deleted it and reinstalled and everything under the sun trying to fix it.