The ppl at HP (and other places similar) have some really good ideas, and if you stood around outside on the ground floor long enough, guaranteed you'd catch a few as they drift down after having been thrown out the window by the penny pinchers on the 40th floor.
That case is an airflow travesty and the thought process behind slapping a 140w cooler on a cpu that can regularly hit 200w in stock configuration for at least a minute is just mind boggling.
That's throwing gasoline onto a fire in an attempt to put it out...
Op best suggestion I can make is go delve into your bios. Make very sure MCE is disabled, I'd even go as far as disable Hyperthreading if just gaming. And if that motherboard/bios allows look into undervolting just as if you were overclocking. Get the VID down. Streamline the cpu to use less power but maintain performance levels. Turn up the fan duty cycles to spin faster, sooner.
Your case is an oven, the cpu by nature is a blow torch and the cooling supplied is just plain sad. Anything that you can do to increase heat dissipation will have favorable results in many areas. That includes the heat of chipsets like the super i/o, Northbridge (PCH) etc that rely on passive cooling and airflow.