The ID3 tag, attached to MP3's, allows users to specify song title, artist, album, etc. As of ID3 v2, extra information could be added such as images and comments. But with this extended information came the ability to also attach viruses, malware and file locks to an mp3. Some websites such as www.2conv.com and www.flv2mp3.com use the extended format of ID3 v2 to disallow users from removing their information from the comments section or their associated image from a downloaded file.
If you have access to an ID3 tag editor (not merely the values allowed in Windows Media Player or Windows Explorer), you will be able to see the lock on the mp3 file that throws the "a disk error occurred during a write operation" error and remove it.
If you don't have access to an ID3 tag editor, the easiest way is to use iTunes:
* Load the mp3 into your iTunes library Right click on the song and choose "Convert ID3 tags..." (Note - this option only appears from the library selection, not from playlists)
* Convert the ID3 tag to v1.0 - this will remove all extended information from your track such as hidden add-ons, malware, images and file locks
* Convert the ID3 tag back to a v2 format so you can add your own extended data (I like v2.3)
* Right click on the song and use the "Get Info" option to add whatever information you want
Once you've converted the ID3 tag to v1 and back, you will have effectively removed the extended data that prevents changes to the original file, and you will be able to change properties, modify data, rename the file, etc via Windows Explorer without the write error.