Laptop is not so stressed according to task manager and it's just warm so I probably could optimise it a bit. Anyway, I treat it as a lottery that costs next to nothing so the chance of winning is next to nothing.
If you just want to lottery mine you may want to look at sidehack's USB miners, you would be getting GH not MH with just one stick and you could use a super cheap and low power raspberry pi running headless to control it - much less power than running a laptop. Also you could get one of his usb hubs and run a bunch of them if you wanted.
https://bitcointalksearch.org/topic/announcing-gekkosciences-new-usb-stick-miner-the-aptly-named-newpac-5053711