Boot problem

[Ballz]

Specs:

Intel i7 3.40 Ghz
ASus P67 sabertooth
Corsair vengeance 8gb

I have a slight problem as my system starts for a few seconds, turns itself off then restarts almost immediately & loads windows 7 with no problems.

Any ideas?

Thanks in advance.

 

[Ballz]

Thanking you.