I just bought a Windows XP Media Center pentium 4 computer from Dell. I am using Nero 6 as a burning program. When I try to put files on a DVD rw or CD rw disk which I've just erased so that it is clean, no problem. The Nero software says I have to burn it or the Windows CD burning wizard comes on if I just add the files without using Nero. In either case after I either burn the RW disk through Nero or Windows and then try to add another file to the RW it says I must erase the previous files (Nero) or the Disk is full (Windows Burning Wizard). What to do?