problems w/ properties and previews

Hi everyone, this is my first post here, and I need a little help. Just recently, when I try to change the properties of an mp3 file, I run into two problems. First, as soon as I click on properties the file opens and starts playing automatically even if no program is set to associate with that file type and even if all my autoplay options are turned off. There is a new second tab that lists the file name and plays the file with some unknown player. When this happens, if I accidentally close the properties window w/o stopping the playback, the file will continue to play even over top of other audio files until the song is over. Second, as soon as this started happening I find I can no longer change any of the properties of the mp3 file when I click on the details tab. Is there any way I can turn of this preview tab/function, or preferrably permanently eliminate this preview tab? Thank you in advance for any advice which might be forthcoming.