I also recently took apart my collection of old tracks from my iPod. I am using an AIMP player which has encoding tools. So I easily changed the format from mp3 to mp3 and created a music logo. This process takes a matter of minutes.
I had a similar problem with Windows Explorer. I used the recovery point of Windows. Deleted files were restored using Uneraser. Problems in the Windows Explorer Explorer may indicate viruses on the PC.