My computer keeps locking up recently.

My computer kept locking up recently and its never happened before. I still have the same set up since three years ago the only thing new that I added was a cooling fan. My specs are:My specs are:
NXZT Phantom 410
Hydro Series H75 Liquid CPU Cooler - Corsair
Intel(R) Core(TM) i7-3770 CPU 3.40 GHz
Geforce GTX 760
ASUS P8 Z77-V LK
16gb ram
Corsair CS 650M Power Supply


I've heard that it can be the Motherboard but I dont think its that but I was thinking if its overheating but I have the computer on all day! I am a storyboard artist so I have the computer on all day almost. So it didn't happened yesterday or the day. Its really really random. It just happened a few mins ago and I turned it on and have been working on the computer for a good while now and it hasn't happened.






This is the event log of when it happens. I just checked this and its the same log on the 20th too but I am assuming this reboot is done by me because my computer locks up and I need to do a hard reboot

Log Name: System
Source: Microsoft-Windows-Kernel-Power
Date: 10/24/2015 2:37:45 AM
Event ID: 41
Task Category: (63)
Level: Critical
Keywords: (35184372088832),(2)
User: SYSTEM
Computer: CloneTrooper
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>3</Version>
<Level>1</Level>
<Task>63</Task>
<Opcode>0</Opcode>
<Keywords>0x8000200000000002</Keywords>
<TimeCreated SystemTime="2015-10-24T09:37:45.595824500Z" />
<EventRecordID>1016</EventRecordID>
<Correlation />
<Execution ProcessID="4" ThreadID="8" />
<Channel>System</Channel>
<Computer>CloneTrooper</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">0</Data>
<Data Name="PowerButtonTimestamp">0</Data>
<Data Name="BootAppStatus">0</Data>
</EventData>
</Event>