Configuring nero 7 burning rom

hi
i was copying dvs with nero burning rom and doing very well.then i got a prompt
just before the burning process saying i was using the wrong mediait said the
media i was using was dvd-r and that i needed dvd-r/rw.if i wanted to use dvd-r
i have to config nero 7 to be able to handle dvd-r.how do i config nero 7 to be
able to do this??thanks

coonsanders