This issue is simply solved by factory reset:
To restoring Nikon D5000 to its default settings, just hold down the [Information button] button and the [Information edit button] button together, until the control panel turns off briefly while the camera resets itself to the factory default settings. I hope this method will surely help you. If still same issue happens then check [http://guideusermanual.com/product-name-d5000-manual&po=4307&lang=English|Nikon D5000 Manual] for help.