Ok here is the problem
 
"Steve" was getting a message when he booted that says "Error graphics card is not connected to the psu"
 
"Steve" has tried installing a molex to pci-e adapter to fix the problem but now he gets these problem
 
his computer lag's and goes black whenever he try's playing games e.g cod 4
 
 
Is it possible for a graphic card to be damaged by not being plugged into the psu? From my experience I think "Steve"has spiked the graphics card by not wearing a anti-static band while installing it?  
 
but what do your guys think a possible cause of this maybe  
 
Regards Andrew
 
btw the psu is a 750watt Zalman

too weak power supply

I forgot to say that the psu is a 750watt Zalman psu

Hmm, Maybe you should try your video card on a different setup.

I have and the same problem occurs meaning it must be a video fault