you surely must have win 2000, go chek the tutorial on how to boot your images on win 2000, didn't work for me but you can try it, maybe you'll have chance
I think it´s a non-bootable image. Chanka does not support non-bootable image or boot cd. I have heard, that the Dreamcast Utilities are support this. If you have a original dreamcast use the boot cd and test it. If it runs than you know the problem.