I have bought a new PC

I have bought a new PC & Laptop as my old PC just 'died' on me.....unfortunately I had 90GB of music on myITunes,which I can't access.....is there a way to retrieve it from there,and put it on my new PC.....also, I am a single mum ,with a daughter,who has IPad,IPOD, and netbook,but is not yet old enough to have her own account...I have a new PC, laptop,IPOD,and netbook...so how can I have ITunes with all of these devices needing to be authorised ...I pay the annual fee for the ICloud, but can't take full advantage of it, beause only it appears that only 5 devices can be authorised.....in this day & age of increased technology the maximum amount of devices that can be associated with the same account should be increased....especially if users are subscribing to the ICloud service....Can anyone help me with this??