The woman was sitting in front of her apartment at 1133 Meadow Lane around 6 p.m. when the suspect approached her, pulled out a handgun and demanded that she hand over the computer, police said.
She refused, and the man hit her, police said. When the woman screamed, the man ran away.
Police said the victim suffered only minor injuries and did not require medical treatment.
The suspect is described as a black man in his mid-20s who is between 5 feet 7 inches and 5 feet 10 inches tall and weighs roughly 165 pounds, according to police. He was wearing a black, puffy, hooded jacket and dark jeans.
Anyone with information about the case is asked to call the Concord Police Department at (925) 671-3220.