Originally Posted by
DratUK
Can you post your full system specs ie Ram type make speed, PSU Brand model CPU Heat Sink..
If it is shutting down immediately then check all cables are correctly seated, that the CPU heat sink is correctly installed.
As Buff has said check that you have set the RAM voltage in the bios to your RAMs rated voltage.
To me from your posts it could be the CPU Heat sink dose not have proper contact with the cpu and is shutting down. Check your temps in the bios if it gives enough time before it switches off.