laptop make and model, please..
Have you changed any hardware or software before the problem occured?
Try powering down your computer. Turn it back on and tap the F8 key..When Advanced Options appear, select "Last Known Good Configuration"....
If that doesn't work power down get start computer again and get back to the Advanced Options menu, and select "safe mode with networking"...When you are totally booted up and logged in...Do this:
Click START, control panel, on the left-hand side click on "classic view", find Device Manager and click on that...When Device Manager opens click on the "+" sign next to "Display Adapters", right-click on the item in the submenu and click update, and see if Windows will find an updated video driver that might fix the problem...
