remove backtrack from hard disk unetbootn
So i used unetbootin and I put the ISO on my hard disk, so when I rebooted the computer I had aditional options like booting unetbootin and backtrack, for some reason backtrack doesn't boot, it says I have to load kernel first. And when I chose Unetbootin from the grub splash screen it loads backtrack, and I am unable to install backtrack because I can't unmount a drive.
Anyway all I want to do now is remove everything I did with unetbootin, just remove backtrack and everything I did.
I'm a noob at this, how can I undo the stuff that unetbootin did?