I'm assuming you're talking about cinder block walls all the way up, so that inside the room, the windows are set into cinder block exterior walls, and the cinder block is just painted...am I picuring this correctly? If so, then what I mean by furring them out is attachimg vertical wood (or metal) "studs" to the cinder block from floor to ceiling, placed 16" on centers. The thickness of the furring depends on how much insulation you want to apply. Box extenders are available for all electrical boxes, and typically there's enough slack in the wires so little or no actual wiring need be done (depends, of course on how deep you want to furr and what you find when you open the boxes). Then install the insulation, then drywall or panel it. Voila! A slightly smaller room with newly insulated exterior walls and a whole new look. Some clever trim work around the windows, new baseboard, etc. I imagine that with a few google searches along the DIY lines for finishing basements & stuff will lead you to all sorts of pics and tips and such on furring out a masonry wall. It's very commonly done to finish below-grade basements. Good luck! Rick
(Not sure how this got into the Green Room, I could've sworn I put it in DIY. Maybe BeGreen re-moved it, dunno.)