My 15-year old son, who looks older, just signed a contract to purchase a computer. Is the contract valid?
No, the contract is not valid. As your son is a minor (under age of 18), he is not old enough to enter into a legally binding contract without parental consent except for "necessities" . The computer is not a necessity. The store will have to refund the payment he made, regardless of their return policy, when he returns the computer.