The touch screen fits in the lower or bottom half of the Nintendo DS Lite. It is stuck on top of the lower LCD (the part that lights up and shows the image) with a frame of adhesive, like a sandwich. If you tried to re-calibrate it through the DS Lite menu, and it still doesn't respond correctly or at all, or is simply cracked or scratched badly, replace it!
The lower LCD is not included -- see link below to purchase that separately. Outside professional installation recommended if you are not a handy, DIYer. If you wish to install yourself, you will need a special tri-wing security driver tool to get inside the Nintendo DS Lite (see link below). Once inside, you will need a tiny #0 phillips screwdriver.
Be sure to remove the protective flexible plastic film that is on both sides of the touch screen, right before installing.
Also, check our FAQs under Information to see tips on doing the repair.
Please note this part fits the Nintendo DS Lite, not original DS or DSi or DSi XL.