|"motherboard is Intel BTHC152002a4....."|
Incorrect model number. Intel desktop motherboards start with a D followed by the chipset number, so your board's number should be something like D946Gxxx. Here's 3 possibilities from the Intel site:
Intel® Desktop Board D946GZAB
Intel® Desktop Board D946GZIS
Intel® Desktop Board D946GZTS
When did you install Win7? It's doubtful there ever were any Win7 graphics drivers installed for the motherboard graphics - it's too old. Your best bet would be to install a Win7 supported video card.
See the following: http://downloadcenter.intel.com/Det...