Im having a hard time using nikon D40 M mode, daylight indoor, aperture is 4 speed is 1 still da imge is dark

It seems you're having problems because A) the lens cap is still on; or B) you don't know how to use your camera in manual mode (M). If you are not aware of the exposure scale, you can't just use manual mode. You can't just pick settings that seem like they might work, ignoring the light meter. You have to set the camera for the right exposure. To do this, you should read the owner's manual. It will tell you everything you need to know about using manual mode. (it would take me entirely too long to explain the light meter scale to you) Why are you using manual mode, anyway? There really isn't a need, considering there's A, S, P, and all the other moron modes you have to choose from. Here's a helpful hint for you: If you don't know what you're doing, leave the mode dial on the green box.