Well there isn't much you can do in the line of modifications to a Notebook for Bitcoin Mining. With that sort of set up you are stuck at what you are currently getting.

If you are serious about mining and are wanting a return you should check out the listings that are kept on https://en.bitcoin.it/wiki/Mining_rig they hold cost and effectiveness breakdowns on machines. The best bet for mining bitcoins seriously is building a desktop from the ground up with the specifications listed there.

Best of luck!