PC Randomly Reboots Itself

So for the last two months my PC has been rebooting itself about once a week. Sometimes i can be on it all day till it happens and others it will happen within an hour after turning the PC on for the first time. I did go for almost three weeks without a reboot but than it started up all over again recently.

At this point i don't know what the heck it might be. I did remove the PSU and tried the PSU that came with the computer and it still happened. Someone told me that it was a software issue but how do you even go about figuring out which software it might be.

Hope you all can help me cause this is driving me nuts. Also would like to figure it out before something gets seriously damaged.

This is what even viewer shows:

Log Name: System
Source: Microsoft-Windows-Kernel-Power
Date: 10/13/2014 3:59:10 PM
Event ID: 41
Task Category: (63)
Level: Critical
Keywords: (2)
User: SYSTEM
Computer: 1Win7-9510
Description:
The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed, or lost power unexpectedly.
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
<System>
<Provider Name="Microsoft-Windows-Kernel-Power" Guid="{331C3B3A-2005-44C2-AC5E-77220C37D6B4}" />
<EventID>41</EventID>
<Version>2</Version>
<Level>1</Level>
<Task>63</Task>
<Opcode>0</Opcode>
<Keywords>0x8000000000000002</Keywords>
<TimeCreated SystemTime="2014-10-13T20:59:10.960009600Z" />
<EventRecordID>3506</EventRecordID>
<Correlation />
<Execution ProcessID="4" ThreadID="8" />
<Channel>System</Channel>
<Computer></Computer>
<Security UserID="S-1-5-18" />
</System>
<EventData>
<Data Name="BugcheckCode">0</Data>
<Data Name="BugcheckParameter1">0x0</Data>
<Data Name="BugcheckParameter2">0x0</Data>
<Data Name="BugcheckParameter3">0x0</Data>
<Data Name="BugcheckParameter4">0x0</Data>
<Data Name="SleepInProgress">false</Data>
<Data Name="PowerButtonTimestamp">0</Data>
</EventData>
</Event>