Hello all. I have searched and come up with numerous answers on this subject and am even more confused than before. I undersdtand what r and rw mean for a disk. How come on a new computer, that is cd rw some cd's still will not work. While on other computers they do, and those computers are from the same company and not too old? I have a brand new external cd dvd r/rw player and there are some dvds that it says it can not read. I have a dvd/rom at home, and it will not read some disks. This seems ridiculous tro me that you can buy or burn disks for backup and there is a chance they will not work. I am ready to upgrade to 750 zip disks. They are so easy to use and make cd and dvds look lame and put them to shame, IMO. Is ther an all-in-one cd dvd player/reader and one standard type of disk to buy that would guarantee playing on almost all platforms?