Please help: GPU Overheated

EDIT: Ok, don't know wtf I did, but it sits idle at 59 Celsius (was 76) and gets up to a max of 90 degrees Celsius (was 104) Definitely not going to argue with it though. Thanks for all the help and opinions.

Hey everyone. I really need help. I just purchased a gaming laptop (used) and have had some pretty bad overheating issues. I downloaded MSI afterburner to figure out the temperature that my GPU was getting to. Idle, it reaches 75 degrees celcius and when I'm gaming (Diablo 3 mostly) it gets to a WHOPPING 104 degrees! The reason this is an issue is because when it reaches 104 degrees, which is common, the computer automatically powers down the GPU which results in major fps drops, down to 1-5 fps for around a minute at a time. I have to alt-tab to let it cool down. I really need some ideas on what I can do.

This is what I've tried so far:

1. I have taken the laptop apart and cleaned the fan and all ports with compressed air.
2. I have purchased a $40 laptop cooling pad that doesn't seem to even reduce the temperature by a degree.
3. I have ran 3 different antivirus programs to make sure a third party software wasn't causing the overheating.
4. I have reduced my graphics to low everything and am still at 104 degrees.
5. I have tried increasing the fan speed through the Nvidia control panel, but it is blocked for some reason. Here is a picture of what I'm looking at: http://i.imgur.com/OpWsD.png
6. Updated to the most recent drivers.
7. I have tried undervolting

None of these have helped in any way, sadly.

Here are my computer specifications:

Asus G72gx Gaming Laptop

Intel® Quad™ Core Processor Q9000 : 2.0 GHz 17.3" Full HD (1920x1080)/HD+ (1600x900) Color-Shine (Glare-type),Asus Splendid Video Intelligent Technology NVIDIA® GeForce® GTX 260M with 1GB GDDR3 VRAM

I really need help with this. I can't seem to figure out what to do.

I will try any suggestions!

Thanks a ton!

P.S. Can anyone tell me why I can't adjust the fan speed either?

Trenton