You have not told us what operating system(s) you are using, but assuming that you are using some version of GNU/Linux then the following generalized method should work:
- Using your installation media boot into linux rescue mode. You should end up at a root shell prompt with your root file system mounted somewhere like /mnt/sysimage.
- chroot /mnt/sysimage (or whatever is your mount point)
- grub-install /dev/hda (or whatever is your boot disk)
Obviously, if you tell us more about your particular configuration, we can provide more exact or more appropriate instructions.
thanks for your response, im using Ubuntu 10.4, and luckily its not my boot disk thats failed, but my secondary data HDD. Have a backup of most of it, but the newer stuff (ie my current work) is only on that disk. of which i cannot use.
disk is a 250Gb WD Scorpio formatted with a single NTFS (came out of my windows box) partition taking the entire disk