CPU is not upgradeable on a laptop unless you are prepared to pay serious money to have a laptop technician do it for you. The CPU is soldered to the circuit board and requires skilled knowledge to remove & fit a new one without damaging the board.
That's why it pays to buy a laptop with the most powerful CPU you can afford, even if you don't need that much performance at the time.
That's why it pays to buy a laptop with the most powerful CPU you can afford, even if you don't need that much performance at the time.