Previously Working Computer Now Infinitely Reboots

[FreezerburnV]

The thread title says it all. I have a computer which yesterday was working perfectly. I played some Tribes: Ascend and Diablo 3, and everything was smooth and awesome. I get up this morning, turn my computer on, and it goes into an infinite reboot loop for seemingly no reason. Nothing has changed between then and now except that I turned my computer off. The specs of my computer are:

OS: Windows 8 (64-bit)
CPU: Intel i5 2500K
RAM: 8 GB G.Skill DDR3 1866 (2x 4 GB)
Video Card: EVGA Geforce GTX 560 ti 1 GB VRAM
HDD: Western Digital Black Caviar 1 TB
DVD Drive: Something older, not sure. Unplugged it and no change though.
PSU: CORSAIR Enthusiast Series 650W (this is a few years old right now, because the new one I ordered was dead and I need to get it replaced)
Motherboard: ASUS Sabertooth Z77
I also have a Cooler Master tower with 3 230mm fans (and 1 200mm I think?) which are all hooked up, if it matters.

Before posting this, I have tried to use only 1 stick of RAM and move it between all the slots, with no success in fixing the problem. I also disconnected/reconnected the main power cables from the motherboard (this has fixed problems before, for some reason), as well as the same with my video card. All without success. I also attempted to remove the stuff plugged into the motherboard directly, still no success. If you have any ideas on what might be wrong, or a way to fix this, or something, I would REALLY appreciate it.
Also as another note the BIOS boots fine and I can mess with all the settings with no issues. It's only when it tries to boot into the OS proper that the computer restarts.

 

[yougotjaked]

This actually just recently happened to me. I did everything you've done so far, but nothing worked. Try clearing the CMOS and see if that works. If not, take out the CMOS battery and wait about 10 minutes. Then put it back in and see if it works. That did it for me, so it's worth a shot.

- Jake

 

[FreezerburnV]

...ok, I am doubly confused now. I honestly have no idea how this just happened. I decided to try and boot from my OS media to see what happened. It successfully booted into that, and I was about to use the "Refresh" option available on it to get the OS cleaned up and see if that would help, when I saw yougotjaked's post about the CMOS. Looking through my manual a bit, I read about the POST LEDs my motherboard comes with that will stay lit up if there is a problem with something specific. After rebooting the computer, none of the LEDs were lit up, and it booted back into Windows just fine.
The only conceivable thing I can think of is that something went funky where booting was concerned in the BIOS, and booting from a DVD cleared it up. Clearing the CMOS might have worked as well, so maybe both jake and myself actually had the same issue.