>I have this 42 inches monitor running at 1920x1080. The graphics are all ok. Some of the fonts are all ok. But, for all regular text, the font is really bad. I see the current Monitor is set to the Microsoft Plug & Play Monitor. I guess this is what I need to change. What exactly should I do to fix this problem?

Is it monitors native resolution? Did you try ClearType?
What font is used for "regular text" ?