There could be a few reasons why your car is in the drive but won't move. The most common reason is that the transmission is not working properly. This could be due to a problem with the transmission fluid, a broken transmission belt, or a damaged transmission. Another possibility is that the engine is not getting enough power, which could be caused by a problem with the spark plugs, fuel injectors, or catalytic converter. Finally, there could be an issue with the brakes. If the brakes are not working properly, then the car will not move even if it is in the drive.