Uninstall Grub? And Kubuntu on external hard drive?

[blahbah7]

On my laptop I have a dual boot with Vista and Ubuntu. I installed Kubuntu on my external hard drive and it looks like I installed it wrong. I did the regular live cd installation when it looks like I should have done this: https://wiki.ubuntu.com/LiveUsbPendrivePersistent

Now I want to reformat the partition that I have Kubuntu on but I need to figure out how to switch grub back to the Ubuntu on my internal hard drive, how would I switch grub back to there? At the moment I get error 21 whenever I don't have my external hard drive in and try to boot

[Pumalite]

First fix your Windows MBR with installation disk (Recovery>Fixmbr>Fixboot)
Or super grub:
http://users.bigpond.net.au/hermanzone/SuperGrubDiskPage.html
Burn to disk and boot from it. Come back later for the rest.

[blahbah7]

Ok I did that and it worked great, now how do I make it bootable?