New build crashed, won't boot

[hungrybat]

I built the system recently and everything ran perfectly. There's almost nothing on it other than Windows 7 Pro 64 updates and Guild Wars 2. I only loaded 1 driver to get the LAN operational, and I've been playing GW2 flawlessly for 3 days. It went into power-save/ sleep mode for the first time and I had to click my windows username to log back in. Everything came up. I typed a search into the Goggle search bar, and exactly as I hit enter, I got a blue-screen.

I suspect it's the motherboard because there are some known issues with the model. It's had the latest F8 BIOS the whole time and running without a hitch, so since that should be working, I'm not sure what to do next.

There have been about 10 failed boot attempts since the crash. I got these results in order.:
- Windows failed to shut down properly, I chose a normal startup rather than safe mode. Got another BSOD, something about dump or check.
- Asked me to repair Windows, so I chose that.
- Would hang on Gigabyte BIOS screen. I got "A2" mobo code which is: "Detect and install all currently connected IDE devices." about 3 times in a row.
- Boot loop: keeps rebooting after flashing Gigabyte splash screen.
- Last attempt I tried a BIOS fix I read on AnandTech to enable onboard Intel graphics. Now I get error "96" which is "Assign PCI device resources" and it continues the boot loop with the intermittent splash screen.

I have no idea what to do, so I'm asking for help instead of fiddling with it. I'm kind of panicked here, so I'd be grateful for some wisdom. Here's my system:
i5-3570k at stock
Gigabyte UD5H
8GB G.Skill Sniper
MSI 660Ti
Windows Pro 7 64 bit
Corsair HX750watts

I can get into BIOS, but that's it.

[Deleted]

Do you have a SSD? These don't like to sleep. Might be your error right there.

[Ryuukon]

Reseat your CPU. Sounds like it's not seated right. Check for a possibly bent pin too. Also reseat your DIMMS too, just to be sure.

[hungrybat]

@Marest -- I do have an SSD: Crucial M4 128. What can I do to make it boot, then turn off the sleep mode?

@Ryuukon -- Would the computer run for 3 days if it was the pins? I'd rather try other measures before fiddling with that because I had a whale of a time installing the cooler. RAM is easier, but same question regarding the hardware.

UPDATE: I cleared the CMOS, now it hangs without letting me get into BIOS with code 79 "CSM initialization is started."

[Perderder]

Unplug all of your USB devices. Remove all of your RAM except one stick. Clear CMOS. See if the system will boot.