FPS is soo broken plz help!

Hey i recently got a new pc, the specs are below

Intel core2 Quad 2.4ghz
MSI P7N SLI mobo
3gig (there is 4 but xp home 32bit) ram
2x Nvidia Geforce 8800 GT (Fatal1ty 1gb) SLI
3 HDD 80gig system drive, 700gig media hdd.

now my problem is that all my games even low spec games like Audiosurf and warcraft 3 have big lag spikes, and any new game i buy which my pc should run easily. however as soon as i play a game it will be fine, nay, perfect for 5 seconds then my fps will drop to 5-12 fps (normal around 60+) this makes the game utterly unplayable. this happens with all of my games.

i have tryed defragging, hdd check, disabling sli, disabling physx, using different inagme settings. and this problem will happen even if all of my settings are low. ive disabled every program other than system programs and the game, doesnt work. everything i have tryed does not effect it at all and it seems to get worse.

ive run every virus scan under the sun, avg, norton, spybot SnD, windows defender. nothing is working someone have a solution please!

they are upto date just checked again

your PSU is prob overloaded and is throttling down , or your overheating and throttling down , both can cause a drop in fps after your system realizes the problem and uses its failsafes

Probably you used hard drive from old build without a reinstall of windows and you have major conflicts.

I would check your temps of your CPU to be honest.
Its cutting the clock speed of the cpu to cope with heat.

By the sound of what i read from your post, it looks like the problem.
Could be a badly fitting heatsink and fan.

Check your cpu temps idle, then when playing games.

Thats a badly seated heatsink.
85 c way too hot even at idle.

You dont need a new heatsink and fan at all.
You need to take it off, give it a good clean and re-apply some thermal paste to the cpu.
Only use a small amount though as putting too much on causes heat build up.
About the size of a grain of rice should do it.
Then spread it over the whole cpu in a thin layer.
Slapp the heatsink back on and double check it is firmly locked in place.

K buddy...

No problems ! glad i could help you.