Here's my situation.
I had dual boot vista and Backtrack5-r1. After reinstallation of Vista. I got error saying:
error: no such partition
grub rescue> _
even though I have completely reformated the HDD and installed a fresh Vista.
help command is unknown, nor /?, but ls command shows:
grub rescue> ls
I have googled and tried a few with no success, it keep showing me "unknown command"
I have a bootable BT on USB.