2000 server not booting in diff hardware

i have win 2000 advanced server with service pack 2 and tried to connect the hard disk to another p.c. both are p IV and intel machines having 256 MB Ram but different VGA cards and mother boards. While booting in a new machine,inaccessible_boot_device error appears. It is not starting in safe mode also. Can anyone help me how to activate a working hard disk with windows 2000 advanced server in another machine.
Thanks in advance.