Kernel Power Error: Help!

Look, I’ve tried everything. The rig is brand new. Everything is plugged in exactly how it should be, and I've even installed the latest drivers for every single component. But the second I launch a game, the whole thing just resets itself. Sometimes it happens after five minutes, sometimes it takes twenty, and occasionally I can get two hours out of it before it dies. The bottom line is that it keeps resetting constantly, and it's driving me crazy.
Here is what popped up in my Event Viewer:

Log Name: System
Source: Microsoft-Windows-Kernel-Power
Date: 6/23/2014 5:11:41 AM
Event ID: 41
Task Category: (63)
Level: Critical
Keywords: (2)
User: SYSTEM
Computer: Richard Myers5-PC
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="2014-06-23T12:11:41.490410500Z" />
<EventRecordID>91092</EventRecordID>
<Correlation />
<Execution ProcessID="4" ThreadID="8" />
<Channel>System</Channel>
<Computer>Richard Myers5-PC</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>

Maybe just run a memory test using "memtest" to be safe.

I skipped that one specific test because, honestly, I have no clue how to navigate that software. I went ahead and stress-tested the GPU and the processor, covering pretty much everything except the RAM. I mean, how else am I supposed to test the memory when MemTest is just a complete and utter mess to wrap my head around? It's way too confusing to actually use effectively.

Memtest is actually a pretty straightforward little tool—you don't need to be some tech wizard to get it running. If you check out this video clip, you'll see it's pretty simple: just burn it onto a blank disc to make it bootable, then head into your BIOS and set the CD/DVD drive as your primary boot device before saving. Once you do that, the program will kick off automatically and start scanning your RAM. If it hits any snags, it’ll throw an error message your way.

http://www.youtube.com/results?search_query=memtest86