I downloaded a song from iTunes and it won't play. Whats up? I tried everything on iTunes' troubleshooting list and everything on that list was useless because all of the questions were like, for example, "you have too many computers authorized," whereas I just have one computer authorized for iTunes. All my other songs play and I paid for this song so I want my money's worth.
Someone else must have activated your account in more than 5 computers. First of all, go to iTunes and sign-in to your account. If you have authorized 5 computers (it could be computers you do not even own anymore) you need to find a button that says "de-authorize all my computers".
Once you do that you need to authorize each computer later. Then you'll be able to play the song. Good luck :)