I need a robust reliable way to protect just a single file from being copied. Whether its prevent it from being copied off a users hard drive, or keeping it on a cd and preventing them from copying the file to their hard drive and from copying the cd. Once I give them the file on a cd I don't want them to be able to make any copies whatsoever. Theres no software involved here, except if some little program could be put on the cd that would transparently help in preventing copies.