my apps wont install or back up to iTunes. not authorized

[Johnny|lucidcomposure]

Ok I formatted the computer yday ad I have installed everything back on it.
about 2 hours ago I restored the iphone and backed up from a previous back up.

I can't store apps on itunes when I have bought them from the iphone and I cant install them after downloading them from itunes.

In my account it says I am authorised to use 3 computers..

No idea what I am suppose to do here?

 

[Johnny|lucidcomposure]

I can play music fine.
iTunes store account wont give you the option to clear the authorizations until 5 are used.
Plus you can only do it once a year.