A fairly common handyman job is to repair squeaky floors. This happens when the floor is on joists, and a prime location is at the stair landing. It is the perfect area for kids to jump over the last few steps and land with their full weight on the landing.
The squeak noise comes from movement. So to stop the noise, you have to stop the movement. A stair landing is fairly small, but regardless of where the squeak is, the process is the same. You will need to roll the carpet and pad back once you find the source of the noise. If you were to remove the carpet and pad, you would see a line of nails as they were shot into the joists. Some hit the joist and some do not…carpenters move fast and “bump fire” the nail gun which isn’t always very accurate.
Stand on the floor and move your weight up and down. You will hear and feel the floor moving slightly. Keep moving until you can isolate the noise. Drive a deck screw through the sub floor and into the joist. The threads will pull the floor down on top of the joist and hold it. Move your weight up and down again to verify that the noise is gone. It probably makes sense to walk the entire floor to check for any other noise since you have the carpet pulled back. Once you are done, if you don’t feel comfortable placing the carpet back on the tack strip, you can hire a carpet company to finish up.