No question it is powered off, it is not in sleep mode. I can duplicate it by changing my system clock to just before 3am, then shutdown. When it powers up on it's own I see the option to go into bios, by pressing F2.
wake source event viewer, had no entries when changing the filtering. The event viewer is how I know when the computer boots, the first entry is
Log Name: System
Source: Microsoft-Windows-Kernel-General
Date: 12/29/2012 3:00:24 AM
Event ID: 12
Task Category: None
Level: Information
Keywords:
User: SYSTEM
Computer: 5AcresAuto
Description:
The operating system started at system time 2012-12-29T09:00:24.109999300Z.
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
<System>
<Provider Name="Microsoft-Windows-Kernel-General" Guid="{A68CA8B7-004F-D7B6-A698-07E2DE0F1F5D}" />
<EventID>12</EventID>
<Version>0</Version>
<Level>4</Level>
<Task>0</Task>
<Opcode>0</Opcode>
<Keywords>0x8000000000000000</Keywords>
<TimeCreated SystemTime="2012-12-29T09:00:24.718400400Z" />
<EventRecordID>318835</EventRecordID>
<Correlation />
<Execution ProcessID="4" ThreadID="8" />
<Channel>System</Channel>
<Computer>5AcresAuto</Computer>
<Security UserID="S-1-5-18" />
</System>
<EventData>
<Data Name="MajorVersion">6</Data>
<Data Name="MinorVersion">1</Data>
<Data Name="BuildVersion">7601</Data>
<Data Name="QfeVersion">17944</Data>
<Data Name="ServiceVersion">1</Data>
<Data Name="BootMode">0</Data>
<Data Name="StartTime">2012-12-29T09:00:24.109999300Z</Data>
</EventData>
</Event>
