Vista/N360 font size problem

I seem to have an incompatibility issue with Vista/Norton 360 4 and would be grateful for any help. I have my Vista fonts set to custom scale to 144 dpi, but Norton appears to be oblivious to my system settings, it occupies only about 25% of my monitor screen area, and the font sizes are very small and uncofortable to read. Has anyone come across this problem and found a solution? Changing the custom dpi to a smaller setting is not a practical option owing to poor vision.  Thanks.