I do not think that I used compressed air before Afghanistan, but I was ashamed of how much dust came out. I tried that with mine before and I only saw water vapor blow out. The same happened with Dad's. Both are HPs, this one is the HP Pavilion dv7 and this is its service manual, which has instructions for replacing the fan:
http://www.hp.com/ctg/Manual/c01689926.pdf
If working on a laptop is not bad enough, this requires removing the motherboard! HP does not sell the fan anymore, but I can order a new one from China for eight dollars, it would just take weeks, although the shipping is free.
Since the laptop works perfectly as long as I keep it on the cooler pad, I am just going to do that! I am not taking apart the entire laptop for an eight-dollar part!