DO NOT remove the heat sink. You definitely DON'T need to do so, EVER!
You only remove the heat sink if you want to replace it by another model or replace the CPU.
Check for dust accumulation on the heat sink and that the fan works properly. You NEVER need to actualy remove the heat sink for that.
If there is dust, blow it away using a can of compressed air.
It may not be an overheating problem as it restart right away. Normaly, an overheating shutdown appens after some 15 to 20 minutes of use and don't restart immediately, it waits for the CPU to cool down first.
In your case, it looks like the computer get an eroneous restart command, or a service fails and is set to restart the computer instead of restarting the service.
When starting, hold down the Ctrl key. This prevent most startup items from loading and starting.
Does it solve the problem?
If so, start by moving all items from the startup folder to some other location.
manualy start one of those items. If the problem return, you have found a faulty application.
You need to uninstall it OR repair the installation.
If it's a preloader or "startup accelerator", just remove it, you realy don't need those.
Next, start in safe mode.
From here, DISABLE the rest of the various startup items. Look for any application or accessory that want to start with Windows and disable them, ALL of them except your antivirus.
Next, open the Run... dialog and type
%SystemRoot%\system32\services.msc /s
This opens the services manager.
Look for the following service:
Remote procedure call (RPC)
It's a core service. Almost all other procedures and services absolutely need that service.
In the recuperation tab, it MUST be set to "Restart service" on all 3 lines.
Sometimes, it's set to "Restart computer". If that's the case, you often experiment your symptoms.
Electro, January 2012
