Q: why does my itunes account say my computer is not authorised when it is??

Hi Tony, 

When playing your purchased content and you are constantly getting the pop up to Authorize, then take a look at the article below to give some troubleshooting options. One is to make sure signing in with the correct Apple ID if you have more than one account of purchased content on your library. If it is just the one account then you may need to remove the SC Info folder and then sign back in and authorize the account.  

iTunes repeatedly prompts to authorize computer to play iTunes Store purchases

http://support.apple.com/en-us/HT203160

Take it easy,

-Norm G.