Laptop overheats to 103C and performance suffers dramatically

My laptop's been overheating in the past week and sometimes it jerks doing even the most basic tasks. when I load a basic game (NHL 09 in my case here), Speedfan tells me my Core is at 103C, GPU 107C, HD0 63C Temp1/2 80C.

At idle it's Core 79C, GPU 84C, HD0 64C Temp1/2 also 80C.

I have a HP CQ50-110US and although I've known that HP laptops have a terrible design and tend to overheat (had my laptop get hot in the past, but never to the point where i'd lag loading my browser and closing a tab).
When it's idling, it merely makes my palms fairly warm, and when I try to play any game, the entire thing feels like it could fry an egg but it continues to function (at 5 frames perhaps). The fan does appear to be moving and blows out air but I'm guessing it's got to be my problem.

I've used compress air to clean out the fans/HD, use a metal rack to suspend the laptop, and done the usual software things (malware, defrag).
To make things difficult, the fan's also extremely difficult to reach. After seemingly removing every screw, I could only pry it part way open.

What would you recommend as a next course of action?

 

Take it apart and change the thermal paste. Make sure the paste spreads well (take the heatsink back off after you apply the paste, check, then clean and re-apply paste).

If there is a thermal pad on the GPU or CPU, use a copper shim to replace the pad.