Often that depends on the TYPE of CD or DVD you are writing to (for instance many if not most CD Players will not play CD-RW disks) as well as the capabilities of the player.
If you are not FINALIZING a CD it will not play on many readers.
If you are using packet writing software the disk will seldom play on a reader and often will not be viewable on any other computer lacking the same packet writing software.
Tell us more DETAILS such as the software you are using and the exact process you are performing to write the disks so we have a better chance of telling you what you are doing wrong.

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