Depends what you mean by pixellated. Seeing ghosting on your screen can be caused by a monitor with a slow response time…if the response time is 12 milliseconds or more, you may see ghosting on the screen.

If you mean some pixels are stuck on white or black that’s a different matter. Dead pixels on an LCD are pretty darn annoying. If they’re simply stuck sometimes gently massaging the area can help. There are a few programs that will sweep your screen with patterns of different colours to try to unstick the pixels, like JScreenFix (http://www.jscreenfix.com/) or SourceForge’s Stuck Pixel Sweeper (http://sourceforge.net/projects/stucksweep). If it’s truly dead, only a new screen will fix the problem.