Well it turns out I have a faulty Motherboard ( Asus P5KC). It's running fine but their is a Capacitor somewhere near the CPU thats playing a merry tune to itself.
I've tried making a funnel but I still cant posatively ID the culprit. I've been doing my best to ignore it including moving the machine itself further away but I think it's going to get the better of me.
The thing is it took AGES to sort my case out with all the cables secured. It's a work of art.
Should I RMA now or have the use of the machine for a while ?
I've had the board about 3 weeks and it was purchased with cpu, psu new HD and memory.
Cheers !