i am having trouble.I have put my dvd writer on the bottom and my dvd rom on top and it did not help. my dvd writer is a liteon dvdrw ldw-451s. i cant burn anything like if it was only a cd-rom thats what it said when i boot up windows xp and recongnize the dvd-rom i am tired of this cause i lost a lot of dvds -r and dvd+r. i dont even read dvds anymore it sucks . please can anyone help me with this problem it would be very apreciated thx. ps:email if u can help.