[header] How to restore a whiteboard [title] Clean you erasers of as much marker dust as possible by brushing, beating, and vacuuming. [step] A lot of cleaning problems actually start with a dirty eraser. Be sure to beat them out, and take a vacuum hose to it as well to get as much dust out as possible. 
Your eraser will suddenly be much more effective. [title] Erase the whiteboard with your dry eraser.