No error 13 is Not a Unlock error it's just a Dash error
what happen is he used the Slayers CD and his Xbox's eeprom is to New and does Not support older Dashies Thus getting a error13
Yeah Gamez, get on the ball LOL JK
but yeah he needs to try to pull out that eeprom if he can when he uses hotswap or fix the dash, and if not then you gott'a solider