In my experience DPI setting is best left alone, because you can get into trouble with some applications. The most common problem being buttons getting overlapped and therefore unclickable.
Screen resolution should be set to the LCD screen's native resolution.
Both WinXP and Win7 allow you to change font size for stuff like program menu or messagebox. This approach serves me well over the years. ImgBurn menu buttons are fine, but everything else is very small.
As my screen capture shows, ImgBurn's font sizes are smaller than Windowns Explorer.