Gaming Computer restarts off Randomly

[zeromac]

Well I'm in quite a mess here because my computer just restarts itself randomly without giving ANY notice at all. After it restarts it always comes up with the message "Windows has recovered from an unexpected shutdown."
It all started after i installed a pirated version of the Sims 3; so i uninstalled it and deleted everything relating to it. I'm pretty sure it isn't a virus because I've scanned my whole computer with Avast and Malwarebytes Anti-Malware.

Seriously, I have no idea what to do and this shit is getting annoying and I'm worried this random forceshutting down is damaging my computer

 

[Originality]

Possible causes for random shutdowns - virus, power failure (from the wall), power failure (PSU voltage drops or surges), power overdraw (when the system doesn't get enough power from the PSU), power phasing failure (motherboard VRMs), "other" hardware failure (e.g. CPU/RAM miscalculation, although that typically results in BSoDs, not shutdowns).

 

[stormwolf18]

try to disable automatic restart on failure, so'll be able to see what is the error message.

Right click on my computer, properties.

In the System Properties window, click on the Advanced tab.

Locate the Startup and Recovery area and click on the Settings button.

Locate and uncheck the check box next to Automatically restart.

 

[zeromac]

It dosent give a error message, thats the thing. It worked fine for ages but then i installed the Sims 3 on my computer. My brother has the exact same computer as mine and he also installed the Sims 3, no problems whatsoever for him

 

[Legaia]

http://www.combofix.org/download.php

use this and you are ready to go again
oh by the way do not use avast try KAV or NOD32