But if the psu is really blown, how did it work before?(for a day or so)

if you mean the CPU heatsink, I did. its ok.

Hey guys. The problem goes like this:

1. I have recently bought and assembled a new PC and yesterday, it just shut down on its own. It was working just fine before, it was built just two days earlier, but I ran the computer without any probems. And yesterday it ust shut down on its own, even though I wasnt doing anything special. Now it wont boot, when I press the button,the system seems to wake up for 1/2of a second and immediatly shuts down.

2. is it normal for a Radeon 4870 X2 to run in idle at 83 degrees C?

Specs: ASUS P6T Deluxe

Core i7 920

Kingston HYPERX 3x1 GB ddr3 1600 Mhz

LC Power 750 Watts

2x640 GB WD Caviar Blue

Sapphire Radeon 4870 X2

Nothing is overclocked or anything. I am pretty sure that all power connections are OK.

Thanks in advance, help is appreciated.

The fact that it told you do "install a decrypter" tells me it was most likely a virus. X360PS3AMD05