I tried change the font size, from 14 to 100, no help.
I don't think the screen resolution is too high. Check the picture in my first post, compare the string "Press F1 for context-sensitive Helps" with the comments on both screen, you should see the difference. Especially in Custom Function Editor window, the comment is in "Italy" which makes it worse. If the font/color can be the same "Press F1 ...", it would be ok.
In the custom funtion editor, is there any way to change the font bigger? It uses very strange font and I cannot change it.
BTW, I use the same monitor in windows XP, everything is ok. It is something related to Windows 7.