changing GRUB from an external hard disk to the internal hard disk of my lap
 

I had a dual boot (windows 7 + debian), both of them installed in my internal hard disk, with the GRUB in it. I have recently installed a second linux distro (mint), but I put it in an external hard disk. Now the GRUB allows me to boot any of the three operating systems, but I need the external disk to do it. It seems that after the mint installation the GRUB is now working from the external disk (if the external disk is not connected, the machine does not boot.) ¿Is there a way to change the location of the GRUB, to the internal hard disk of my laptop?

Thanks

Usually I set the bios to select the first bootable media and active partition. If you had installed mint that way it would have put grub on the external and you'd have it. You can simply add grub (install grub) to any drive but again bios order would affect how grub is calling other OS's.
Grub doesn't get un-installed so if it was on the internal it will still be there.

What happens on some systems is that usb drives may end up being called internal hard drives in bios or bios boot order so again grub would follow what bios reports.

thanks. it worked.