dv6000 laptop overheating problem

I have had my HP Pavillion dv6000 laptop for about a year and a half and for the last 6 months it overheats and shuts down when it is put into "High Performance" mode.  I play some games every once in a while but not too often.  Unless I am playing a game, I always keep it in powersaver mode.  If I start a game that needs more power, I switch to high performance mode and my computer shuts down usually within 20 seconds.  I have cleaned all the dust out with a can of air.  I even removed most of the access panels from the bottom to blow dust out.  There was very little dust.  I have a Targus 2-fan cooling platform, but this doesn't help.

I have been researching and found a few forums that people claim their Pavillions have similar symptoms.  Most of them changed their fan speed to 100% all the time through BIOS and said that it worked, but I cannot figure out how to do this.