Startup Repair Loop, ASUS/INTEL/RADEON PC build

hi there, I'll describe my initial problem first:

Packard bell PC imedia something, radeon sapphire 5670 HD GPU upgrade, recent (Jan 2012) windows 7 64 bit custom install upgrade from vista 32 bit, during which i backed up all files on a Samsung external hard drive, then did a complete hard drive wipe install of windows 7, then put it all back on using software run by the Samsung drive. Went perfectly as planned.
Other than that the PC was stock.

One day playing Cod 8, screen inputs failed, then keyboard failed, then funny smell from PC tower, so I switched it off. After analysis, showed to be PSU fail. I took the opportunity to build a better PC, as this one is quite a few years old now.
So I only used the hard drive (WD6400AAKS), Blu ray reader disk drive, memory card reader drive, and Radeon GPU from the old PC, everything else is new:

ASUS P8Z68-V LX mobo
Overclocked intel i5 processor with artic cooling freezer 13 CPU fan
Corsair TX650 PSU
Antec DF-30 case with 4 led fans
All cables and such are new, and all plugged in correctly

When turned on the first time, all fans on, leds, and everything started as it should have, but NO BEEP, monitor came on, instead of showing initial boot screen, asus version came up, then tried to boots windows, then just as the circles begging to circle the logo, it crashes, screen turns off, then on again, then back to asus screen, the windows screen crashes like before, then asks me to do startup repair or start as normally - NO OTHER OPTIONS. Every time I do this, it says it couldn't solve the problem, and restarts, then crashes, then restarts, then goes to startup repair option again. If i select start as normally, it just crashes again like before then loops back to startup repair option again.

I have tried all options possible after the startup repair fails, including command prompt stuff, system restores, image restores, hardware diagnostics, basically everything. It either fails, then goes back to the startup repair loop, or tells me there are no problems with the hardware, then goes back to the startup repair loop.

I AM AT A LOSS FOR WHAT TO DO. I can't find anything on the web to help, hoping some geniuses on here can fix my problem. I think my hard drive is corrupt, but signs have led me to believe its not completely corrupt - like it will see all the places and times on my hard drive to use when i select system restore, however after a fair time of trying each time, and with multiple possible restore points, it fails every time. I think all the other hardware is fine, and working as it should. I think some of the windows system files were damaged when the old PC's PSU blew while playing COD (it usually handles COD fine).

All and any comments appreciated, ask away and I will let you know if i have tried it yet.
Sorry for the long read! Cheers in advance guys!