Many thanks, forester  - will pop over to C3D, as well.

My motherboard is ASRock N68 -S and my current PSU sits at the back, in the top-left corner of the case (when you view the PC from the front).

Things one learns along the way, eh - only a couple of weeks ago before my Vue troubles I hardly knew anything about computers. By the time I'm done with sorting this out, I'll be practically able to rebuild the damn thing :-) .