No. You can't reinstall XP without a reformat. And it would not help Media Center problems. Media Center in Vista takes a little time to get it set up right. Try opening MC and scrolling down to Tasks, Settings and set everything up again and let it know where your music files are. Use Help for more info. You don't need MC to play music. Use Media Player instead. MP will search for all your music and set up Media Library. Maybe then MC will see it.

hi, thanks...  I have Vista Home Premium .... I was just trying to play music through MC, it finds the song names and all but when u try to play them i get the error... Playing them in media player works fine though