The New York attorney general, Andrew M. Cuomo, announced yesterday that his office had filed a lawsuit against Dell Inc. and its Dell Financial Services unit, accusing them of deceptive business practices and of failing to provide adequate customer service.

At a news conference in his Manhattan office, Mr. Cuomo said the suit came after an investigation and more than 700 complaints by Dell customers in New York State.

“At Dell, customer service means no service at all,” Mr. Cuomo said. “Dell’s consumers were intentionally misled, and they had to pay for that privilege.”

A spokesman for Dell, Bob Kaufman, defended the company’s practices and said that its customers were generally satisfied with the services. “While our customers remain our top priority, Dell will vigorously defend itself in court,” Mr. Kaufman said in a statement.