Green color more dominant? Video card problem?

My dad noticed that the green color has recently become more dominant on my computer. He believes it may be an issue with the hardware. Now I am far from tech-savvy so I cannot really do anything either. Anyway, I have an NVIDIA GeForce 8600M GS (whatever that means) on a laptop. Coincidentally, this happened right after he was doing some stuff on my computer, but he seems to like his theory about the video card having an issue. How can I fix this? Or is it a problem with the stuff?|||1) check the connection from monitor to the videocard (if it is a desktop computer).

2) check the preferences of your videocard. Quite possible, the reason is in color options.|||it sounds like the computer