Either you have some weird disc from some strange manufacturer that isnt bootable, or your cd rom doesnt like the media, or you cd rom is a piece or who knows what else but anyways you could try making a boot disc, either a floppy or cd-rom if you want to test out your system, and then from the command prompt run the setup program on the windows cd you have. I dont see why that shouldnt work but if it doesnt it shouldnt waste too much of your time.