Asus Z53S laptop
Vista Business
All factory standard running all current updates etc
GEForce 8400M G display adapter (running latest driver)


Suddenly tonight the LCD display has become slightly duller than normal and quite pixelated.  It's as if someone has wound down the DPI or I have gone back to looking at an old CRT monitor from the 90's.  Screen size/fonts etc remain normal size as does the size and proportions of any images or opened windows.  Colour is approximately the same just a slight drop in contrast/brightness.

I have had to wind back the resolution to 800x600 so I can see the text to make repairs.

A system restore has made no difference, and the effect is still present when booting into safe mode, and during the start up and shut down windows 'flash' screens.  

I have checked everything I know how to check through the basic desktop settings, through the NVIDIA control panel, and in the Asus 'splendid Utility' settings.  As far as I can see everything is normal.

My 3 year old was doing some gaming earlier (Dora and Elmo) and I fear she has clicked on something she shouldn't have.  I am hoping it is just a setting I have missed and someone can point me in the right direction and I will feel really stupid for missing it!

Alternative I guess is that the display has decided to call it quits.

Any pointers appreciated.