Thank you Ttech. I appreciate your answer. I know how to and have already recovered all the files. I was just wondering for future reference if there is a way to undo what the computer decided to do to the disk. The disk was supposedly "closed" or finalized during the original recording session and I thought that no additional data could be written to it. Apparently that's not correct as something was written to the disk and corrupted the index or whatever file allows the disk to be read by any disk reader/player. But, thanks for your response.