Grub Error 21

[slvr_bangles]

Hi everyone,
I bought a LaCie 250 GB external hard drive a while ago. I though that I would install Linux on it so I could dual boot my computer (my laptop had not much space left, an external hard drive was my only option). I installed Linspire on it but when I tried to boot, Grub gave me an Error 21. Re-installation gives the same results.
I asked a friend and he told me to partition it into smaller fragments. I decided to install Debian while doing so (I chose the Desktop machine partitioning scheme, which seemed to partition my hard drive for me).
Grub still shows error 21.
I´m pretty sure that it is not because it cannot access my hard drives. Through Linspire Live CD (the only way I can boot right now) I can access both my external hard drive and my laptop´s hard drive.
Please help ASAP, any will be appreciated.
P.S. Go easy on me. I´m a Linux newbie.

[devils casper]

re-installing Grub in the MBR of External Disk will solve the problem.
connect external disk and boot up through LiveCD. post the output of 'fdisk -l' command.




casper