mp3 files

[Claret63]

I recently tried to back up my mp3 files onto a detachable hard drive for security. Within the the "My Computer" bit of windows I inadvertantly moved the files from my hard drive to the external one rather than simply copied which is what I intended to do. Having realised my mistake I copied them back and although they show as mp3 files neither Windows media player or other software then seem to be able to play them. Additionally the software I use to manage my mp3 player library does not seem to be able to identify them. Any ideas/suggestions of how to sort the issue gratefully received. Does anyone know of any sites with detailed guidance on managing mp3 files.
Kind regards

[jno]

put this Q into Technology (or the computer subsection) and you're more likely to get an answer from the knowledgeable folks there