A lot of this depends on the model of your laptop. The only thing on your laptop that is likely making any noise while you are recording is the cooling fan(s) for the processor and possibly also the graphics chip.
A few years ago intel created a 'speedstep' technology that allowed the processor to run at one speed when it was on external power and another when it was on batteries. Most laptops of this period had a setting in Control Panel that allowed you to tell the chip to allways run at the slower speed, which usually meant that the fan would never go on.
More recent laptops have a thremostat-controlled variable speed fan(s) and a processor with multiple speed steps. So the goal is to keep the fan from kicking into high speed. For one thing be sure that both the exhaust is not blocked and intakes have a good source of cool air. (So for example placing the laptop on a covered panel of 703 would not be a good idea if it blocked the fan intakes. On the other hand if you cut out a channel so that the air was not blocked it would be OK.) Then go to Control Panel. There you will find a Power Options applet and also possibly a Power Options applet specific to your computer. For example my Toshiba has a Power Options applet that allows me to create different profiles for different uses and to set the processor speed between high, medium, and low for each state. Frankly when raw tracking using an external USB sound module (which I would recommend for recording on a laptop) the processor is not doing a lot of work so the low speed is most likely fine. (On the other hand if you are doing a lot of input processing with your recording that would be different.) As for keeping the graphics card fan from switching to high speed try not using the highest resolution or bit depth. Changing the brightness of the screen, on the other hand, will not help with the fan speed.
