I'm currently using Win XP with the latest version of limewire. My original file, I was D/L to, was limewire shared. I shut my computer down for the night and the next day I went to use limewire, I got the message that file was not valid and I had to pick another download file. I did and I was able to download and play my music. I repeated the above process 5 times. I would pick a file to D/L to and the next day I would get the same message. The other users on the computer have not had this problem. I am the only admin level person on this home computer.