BGE: How to make a Key inactive after pressing another Key? When pressing W a cube is doing a forward movement.
When I press S I want to make the W movement inactive, how do I do that?

And after by pressing W again I want the cube to do a back movement, so to do a different type of movement.
You can use states: In the first state, you have a W keyboard sensor, linked to a motion actuator that moves the object forward, and you have an S keyboard sensor linked to a "Set State" actuator, which will set the second state.

On the second state, you have a W keyboard sensor, linked to a motion actuator that moves the object backward.

That should produce the desired behavior you described.

Here's a demo, if required: logic_brick_key_remap.blend