Server 2008 R2 - Reboots Randomly

Hello,

I have one 2008 R2 server w/the Hyper-V component installed hosting two clients and all went down one morning at around 2am, but as to why I can't say for sure.  Below is the log entry from the hypervisor:

Log Name:      System
Source:        USER32
Date:          10/21/2014 1:43:12 AM
Event ID:      1074
Task Category: None
Level:         Information
Keywords:      Classic
User:          SYSTEM
Computer:      hostname3.domain.domain
Description:
The process wininit.exe (127.0.0.1) has initiated the shutdown of computer hostname3 on behalf of user NT AUTHORITY\SYSTEM for the following reason: Legacy API shutdown
 Reason Code: 0x80070000
 Shutdown Type: shutdown
 Comment: 
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
  <System>
    <Provider Name="USER32" />
    <EventID Qualifiers="32768">1074</EventID>
    <Level>4</Level>
    <Task>0</Task>
    <Keywords>0x80000000000000</Keywords>
    <TimeCreated SystemTime="2014-10-21T08:43:12.000000000Z" />
    <EventRecordID>13628242</EventRecordID>
    <Channel>System</Channel>
    <Computer>hostname3.domain.domain</Computer>
    <Security UserID="S-1-5-18" />
  </System>
  <EventData>
    <Data>wininit.exe (127.0.0.1)</Data>
    <Data>hostname3</Data>
    <Data>Legacy API shutdown</Data>
    <Data>0x80070000</Data>
    <Data>shutdown</Data>
    <Data>
    </Data>
    <Data>NT AUTHORITY\SYSTEM</Data>
    <Binary>00000780000000000000000000000000000000000000000000000000000000000000000000000000</Binary>
  </EventData>
</Event> 

Thanks for the help.