getting grub error 21

[leeyj4951]

After installing dual boot to my portable hard drive,
I get grub error 21 when booting withought my hard drive connected to my laptop.
and yes, i can boot to vista or backtrack with it connected.
i googled how to fix this error, but it only changed the error to 17 or back to 21, that was it.
currently, im getting error 21.
Also, i can't get my hard drive shown on my computer in vista.
i can see my hard drive in disk management, but when i right click on it,
i only see these two options: delete volume, and help.
help~

[xX_Spiidey_Xx]

You didn't do too much SEARCHING, did you?

Whatcha did was install grub (the bootloader) to your external drive. Now none of your operating systems know how to boot when the drive isn't there. If you had spent more time (literally, seconds) taking a look into this problem, you would find that it's a quick, simple fix. Although this tut is for grub 1.5, it still applies to grub 2.0, which is used with BT4. And guess what? It was the first page I came across with my four-word search.

Since I don't want anybody else confused, I'm rewriting this tut a wee bit:

Boot into the original Linux system with the external hard drive still installed (or you can boot from a Live Ubuntu CD).
Open up a terminal window (Konsole)
Type fdisk -l and locate your Linux boot partition from the list Example: sda1 or hda1
Type grub-install /dev/sdx or grub-install /dev/hdx to reinstall or repair Grub!
Reboot and test!
Notes: x represents the drive letter a, b, c, d etc. Replace with your actual drive letter.

xX_Spiidey_Xx

[leeyj4951]

thanks for replying.
yes that was one of seven ways that i have tried.
but i want to ask that for x here,
grub-install /dev/sdx,
did i had to put the partition with windows vista?
or backtrack?
I putted c, which was the vista one.
if I had to put the partition of backtrack,
how do i find out which partition it is installed?
becuase as i told you, i can't see my hard drive in my computer running with vista.

thank you~

i've just tried putting b for x, which is the backtrack partition.
but i'm still getting the grub error 21.
i think it's because this only installed grub or bootloader whatever in my hard drive,
not uninstalling grub in my nomal hard drive with vista.
I'm just guessing, but if i am true,
please tell me how to uninstall it.

to make sure, im writting down what i typed in my console:
fdisk -l sdb1
grub-install /dev/sdb

[xX_Spiidey_Xx]

If you want to "uninstall" grub per se, Micro$oft has written a doc detailing how to restore your Windoze MBR. Assuming you have a Vista Recovery Disc, this tut should be all you need in a step-by-step guide.

If you still want to play with BT4, I recommend using Windoze to fix your MBR, and follow these instructions when you're back in Windoze.

Cheers,

Spiidey