Windows XP SP3 Restarting out of nowhere

[mist_hero]

So... I'm either playing a game or just surfing the web... and my computer just restarts.

GFX, Sound Drivers, DirectX, even the OS is updated. (LAN is being updated as we speak)

Current Hardware :

Nvidia GeForce 9600GT 512MB
Intel Core 2 Duo - 2.33GHz E6550
4GB RAM
Realtek HD Audio

Operating System : Windows XP Professional Serivce Pack 3

Events where it restarts : When browsing with Google Chrome.
When playing Cosmic Break (an MMO)

Any idea what's going wrong?
(I also just cleaned out dust from inside the computer... but the Restarts were already happening before that. Checked to see if it was another Blown Video Card's Capacitors... but they were fine.)

Oh and also, when the computer restarts... its gotta be Powered Off for a few minutes before it actually goes to Boot itself. Otherwise, its powered on and not doing anything.

 

[Mark56]

Follow this guide to find the error information in Event Viewer and put it in your next post.

http://support.microsoft.com/kb/308427

Do you get a blue screen when it crashes or does it just go black?

If it is a blue screen with a lot of text on it then follow this to post your minidump files.

Below the reply box click on Go Advanced.Then scroll down until you see a button Manage Attachments. Click on that and a popup-window opens.

Click on the Browse button, find the minidump files you wish to attach on your PC and doubleclick on it. Normally found in C:\Windows\minidump

Now click on the Upload button in the popup. When done, click on the Close this window button.

Enter your message-text, then click on Submit Message.

 

[mist_hero]

It just blacks out....

...
...
Though. Somewhere, inside the desktop... exploded and produced a 'burned' smell. And from then on, the desktop doesnt seem to turn on.

Using a spare computer to do my tasks.... sadly.
The user that was using my computer said, was just playing Facebook and suddenly something inside just exploded, and the computer turned off. I checked inside if there were any blown capacitors, checked the PSU for any damages, nothing seems to be 'blowned'... So i guess i'll just have it diagnosed by a technician.

 

[Mark56]

That's not sounding good but I would guess it is your PSU. You would need to look inside it to see any burned out components.

 

[mist_hero]

Right, replaced the Power Supply, and bought new fans... although the cords inside are a bit... messy.

I have to check why one of the harddrives isnt showing up at all.