can't play protected AAC files
At some point I upgraded to a newer version of iTunes. I don't use iTunes all the time so I didn't notice this issue right away. I also at some point had to change my Apple ID to the name@ format from name only. Now I can't play over 700 purchased before April 2009 protected AAC files. I tried iTunes match, but it doesn't recognize any of the over 700 songs either. I get a message asking me to enter my password for my name only (no @) user id and get a message that the computer is authorized, but it still won't play the songs.
I went to the iTunes store and none of the 700 songs appears in the purchase history that I can see. However, when I opened up one of the albums I had play radio buttons for each song instead of prices for each one on the right side. I had the option to buy the album and I was able to use my password and get all the way to confirming the purchase before I cancelled so it appears that the account is there and that the album is recognized as being already purchased by me.
I am open to any suggestions for recovering these 700 songs. I really don't want to spend a lot of money buying them again.
Windows 8