PC did Unexpected random shutdown

Hi everyone, hope that you can all help me. Today my PC unexpectedly just restarted by itself after being idle. It did not totally reboot though as it got stuck at start up screen i think. It said something about something not found or detected so i had to reboot the PC for it to power up and log in.

After doing quick search online i found where someone said to check event logs which i have done so. Here are the results. I had a critical event and an error event in the last hour. Would really appreciate it if someone can help me in determining what is going on. Thank you!

This one is for the critical even:

Log Name: System
Source: Microsoft-Windows-Kernel-Power
Date: 3/17/2014 4:13:28 PM
Event ID: 41
Task Category: (63)
Level: Critical
Keywords: (2)
User: SYSTEM
Computer:
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="2014-03-17T21:13:28.117608100Z" />
<EventRecordID>2140</EventRecordID>
<Correlation />
<Execution ProcessID="4" ThreadID="8" />
<Channel>System</Channel>
<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>


This one is for the error:

Log Name: System
Source: EventLog
Date: 3/17/2014 4:13:36 PM
Event ID: 6008
Task Category: None
Level: Error
Keywords: Classic
User: N/A
Computer:
Description:
The previous system shutdown at 3:53:07 PM on ‎3/‎17/‎2014 was unexpected.
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
<System>
<Provider Name="EventLog" />
<EventID Qualifiers="32768">6008</EventID>
<Level>2</Level>
<Task>0</Task>
<Keywords>0x80000000000000</Keywords>
<TimeCreated SystemTime="2014-03-17T21:13:36.000000000Z" />
<EventRecordID>2136</EventRecordID>
<Channel>System</Channel>
<Computer
<Security />
</System>
<EventData>
<Data>3:53:07 PM</Data>
<Data>‎3/‎17/‎2014</Data>
<Data>
</Data>
<Data>
</Data>
<Data>7654</Data>
<Data>
</Data>
<Data>
</Data>
<Binary>DE070300010011000F00350007008101DE070300010011001400350007008101600900003C000000010000006009000000000000B00400000100000000000000</Binary>
</EventData>
</Event>