I have a dell inspiron 11 3000. Gave this laptop to my son a while back. He locked the computer with a bios password and unfortunately he completely forgot it. It shows me a service tag number. i tried calling dell customer service. I gave them the service tag number and the code they sent back did not work for some reason(yes! i held shift when pressing enter after typing in the code). Was wondering if anyone here can help me unlock it for use again?