Freeze and shutdown

can anyone help. having spent a fortune on my set-up I have just upgraded to windows 7, removing vista first. when using cubase 6 in the middle of the production my computer constantly freezes or shuts down without any warning, can anyone direct me in what may be wrong.

Could be almost anything…

Overheating CPU

Memory not seated properly


What spec is it?

Any other suspect software or Overclocking happening?