dvd burning errors?

Im helping a friend set up thier laptop (HP)which has a matsui dvd drive burner /player and has Vista as operating system . have Shrink 3.2 and Nero 8 for the burning programs. Doing the copy then burning process it going thru the copy and then does most of the burn but then at the end, it gets errors and quits the process. This not only has been frustrating but wasteful because have tried different methods including using DVD FAb decryp program and still end up with wasted discs and no finished product. the error points to the burner but why would it get that far into the burn and then error it out??? Any help will be appreciated .