Hi,
it seems to be a grub configuration problem...
can you post your grub.conf (or menu.lst depending on your distro) ?
if you want to know more about how configuring grub, take a look at
http://www.gnu.org/software/grub/man...iguration.html
though the best way to configure it would be by a howto from your distro website (by the way, what's your distribution ?)