Alienware M17x R4 stuck on infinite boot loop

Hi!

Short description: My M17x R4 loads Windows but, after finishing and before going into the desktop, turns off and reboots. Ad infinitum.

Long description: My M17x R4 makes it past the first booting screen (the Alienware logo on a black backgound with the Intel logo on the top left corner and a red progress bar in the lower center), then onto the Windows loading screen, and then, once that finishes (all the little Windows ball are assembled into place and then morph into the actual Windows logo), and right before the laptop goes into the Windows desktop (or the user loading screen if you have multiple users and/or are password protected), it turns off for a couple seconds and then boots again. (To see what happens next, go to the beginning of 'Long description'.)

Issue: Windows finishes loading. Then (before going into the desktop), laptop restarts.

Steps taken so far:

1. Ran full Diagnostics (from the F12 options). No problems whatsoever, but the log says that the test is NOT APPLICABLE to the hard drive, so it just 'passes' the test.

2. Waited through several iterations of the infinite reboot loop. No signs of ever wanting to stop; consistent loading times every single time.

Specs:

OCZ Vertex SSD 120GB

ATI Radeon HD 7970M

Intel i7 2.4GHz

Windows 7 Home Edition

What can I do? I have very important, work-related information of the laptop! Please help

Thank you!