Cant burn DVD's
 

I cant get the movies I've downloaded to burn onto dvd's. My last effort was to use a program called dvd santa. Every time i click on "burn cd" i'm prompted with a note saying please insert a blank dvd. I''ve tried my dvd in both drives but its like it doesnt recognize my dvd in the drive. I have no problem burning music cds. Im using DVD-RW disks. Are these the right ones???

are you sure youve got a dvd burner ? because i could burn cds but not dvds

it says dvdwriter/cd-writer combo on the slot, but maybe I have to do something to load the dvd writer????????