(SOLVED) H61N-USB3 Reboot Loop after Win 7 Install

[Luciel]

Hi Guys,

Specs:
H61N-USB3 B3
i3 2105
Sandisk 64Gb SS (Brand New Model so no dodgy controllers + using an exactly the same one on another same spec machine ( except for different mobo)
4Gb DDR3 1.5v Kingston HyperX
300w TFX 80+ PSU

Machine boots fine, the problem is in the last step of Win7 install (after it asks you to create a user and password and so on and the last reboot before operational) once the final reboot is done, just before the W7 loading screen it reboots and the loop goes on, no blue screen. I´ve tried AHCI and IDE modes, I´ve tried a Crucial M4 128Gb SSD (same problem), running it on a wood bench so rules out short, heatsink and cpu on properly, W7 disc used before and after with no problems only mouse and keyboard pluged in so no other devices, tried not having them pluged in, same thing. Tried memtest for 8 passes, no errors, tried different ram, same problem, tried another same model cpu (bought 2 for two builds) same issue (both cpus work fine on the other build that, as I mentioned earlier runs a different motherboard), checked ram timings, they are fine, checked voltage, fine...

Any ideas or should I just rma this...?

EDIT: Bios revision is F8

[Luciel]

Fixed.

I loaded default "Optimal Setings" on the bios, put everything as I did the first time except this time i used IDE as opposed to AHCI, just for the hell of trying something, and it worked...

...but why on earth wouldn´t it before and why doesn´t it work with AHCI? there´s no ide devices hell, there´s no ide ports on the mobo.

Weird one... furthermore now I´m paranoid about if it´ll fail in 3 months.