hi, i've bought a couple of dvd-r discs and i want to burn some music to them, i can burn cd's i did it yesterday with a dvd+r disc, but with the dvd-r when i choose burn cd in windows media player, choose all songs i want, then it says that i should put an empty disc in the "put disc in this" thingy XD please i need some help... it would help me alot if u could.