Add pasta and hot water to a large microwavable container and lightly stir. Set the cheese sauce powder packet aside.
Heat the pasta and water mixture for approximately 8 to 9 minutes on high. Stop the microwave every 2 to 3 minutes and stir the pasta to prevent sticking and clumping together.
Fish out one piece of macaroni and taste it to make sure the pasta is tender, and stir once more.
Add the cheese sauce powder packet, milk and butter or margarine into the cooked pasta and stir until the pasta is well-coated in cheese sauce and the butter or margarine is completely melted.
Add salt or pepper, if desired.
Serve immediately.