While upgrading to windows 7, a large portion my music collection got all messed up. The first few seconds of a song are switched with parts of another songs. Sound files from a game (CIV4) are mixed in too, its not just music from my library. Right now I have several hundred screwed up songs, is there any way to fix this? It didn't happen to all the songs on my PC, only around 25%. Any help would be appreciated.