So I saw the "possible overheating" thread and that reminded me of my own overheating problems... My laptop is a supposed "gaming" laptop but its silly designer put its ventilation holes on the bottom of the damn thing, where they are blocked by the desk. I use Speedfan to measure the temperature; even when idle Speedfan tells me my graphics card is at 60~ degrees Celsius and my processors sit at around 50. The other day I played CoD4 and I noticed my laptop burning up - I lifted it and touched the desk underneath and burned my hand. Seriously. You could have fried an egg on it. Speedfan was reading graphics card temperature at 99 degrees, processors at 80 and even hard drive at 70.

How detrimental is this to my computer and how to fix? ><

It's NVidia 9600GT, not ATI ><

I would first try another temperature measuring program. Speedfan is known to get wrong readings with some chipsets.

While excess heat isn't good, it's not too much of a danger.
There is a risk of the computer crashing if the heat gets too high, and it may make the computer slower, but otherwise, it's no big deal; I speak from experience with a rather low-spec laptop, and it's own overheating problems. The only problems were the afore-mentioned hysteria-crashing, and my left thigh, which is now quite heat resistant, at the possible cost of scarring.

you'll get problems above 90 degrees celsius because then you're in the territory of the melting point of solder.

Mine gets really hot and turns off :/ Try blowing some compressed air to clean out the vents, it'll help. Also use a cooling mat like this: It won't prevent excess heating but it definitely helps