SuperGRUB disk can do this:
http://www.supergrubdisk.org/wiki/Howto_Fix_Grub
Also it is possible with any Linux CD, but involves commands:
http://www.sorgonet.com/linux/grubrestore/
So i was able to duel boot windows 32 bit/ubuntu 10.04, ubuntu is installed on a external HDD. I Installed windows 64 bit on a new Hard Drive in my computer, so now the duel boot doesn't work anymore, it just loads windows, is there any way i could fix this without having to re-install ubuntu?

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