P-6860FX: Overheating and replacement screws?

I've got two questions. Forgive me if they've already been asked; I tried searching but couldn't really find a definitive answer.

Lately, I have been unable to play demanding games(specifically, COD4 and COD:WAW). I can still play things like Civ4, but for anything that is graphically demanding, my computer will shut off after 10-15 minutes, maybe less. It will play perfectly fine and then suddenly lose power. I'm almost positive it is due to overheating, even though I have an external fan for it( an Antec one). I have tried opening it up and spraying some compressed air in there, but it never seems to be too dusty.

Could it be that I need to reapply thermal paste? I've never done anything like that, but it seems like it might solve my problem from what I've read on these forums.

Or could it be unrelated to overheating? I seem to remember reading something about Geforce 8800s that were defective. I purchased the computer last May.

My second problem - I have two screws missing from the bottom of my laptop( these two). I have no idea how they were lost. It hasn't caused too much trouble. However the top left corner of my laptop can be lifted up, something it's certainly not supposed to do. Is there any way I can buy new screws for this? I think that if I knew what size I needed, I could run to a hardware store and buy some.

Thanks.

 

Try taking some of the panels off the back (or do a complete disassembly) and get a really through cleaning. You would be surprised how much dust can "hide" in our machines.

Also download and run HWMoniter and just let it run in the back ground and then play a game. It will record your max temp and please post the result here so we can see if it really is over heating.

As to reapplying the thermal paste... it wouldnt hurt. The stuff gateway sent them out with is pretty much useless (compared to others available) so replacing it with a good thermal goop would do a world of wonders (will require a complete disassembly to reapply GPU thermal paste)



EDIT (i forgot your screw question)
I believe they are #6 countersink machine screws (about 1/4 to 3/8in long) but you can always take another one out and then go to a store and match them up.

 

Thanks. I grabbed HWMoniter, but I don't have time to play now so I'll try it later. I'm gonna try taking out the screw and running to the hardware store before they close, though.

 

I am running into the same issue with Bioshock. After 15-20 minutes it just shuts itself off and I have to start Windows 7 normally. When I get back to the desktop it shows my GPU running around 62 degrees Celcius. I know that this is due to an overheating problem. I guess I will try and clean the thing out even though the fan is running fine and it's normally super quiet. If it continues I will post that Hardware monitor temperature finding.