Title: detect system font size?
function HasLargeFont: Boolean;
var
fontsize: Integer;
hdc: THandle;
begin
Result := False;
hdc := GetDc(HWND_DESKTOP);
fontsize := GetDeviceCaps(hdc, logpixelsx);
ReleaseDc(HWND_DESKTOP, hdc);
if fontsize = 96 then Result := False
else if fontsize = 120 then Result := True;
end;