can my lite on combo sohc 5232k read/write? I know I burned to the disk before but cant now?

I know that it was not burned the maximum amount of times or even close to . my disk drive is telling me also that a fresh dvd 4.7 maxwell dvd that is supposed to be 16x will not read in that or my optiarc dvd rw ad 7200a . One is a white and one is black and says 'ultra speed rewritable' on the outside of the tray. I do believe its supposed to read and write. how to I delete files from the old rw cd that I know works and write different files to it? which drive name is the read/write cdrw/dvdrom drive?