You should open up your own thread instead of putting your problem on the back of a 10 months old thread by another.
I believe if you want to boot from an external hard disk you need to tell Bios the first bootable disk is the IEEE Lacie drive. You also need to put Grub on the MBR of the IEEE Lacie drive. It appears to me you have put Grub into the MBR of the internal hard disk.
Here is a temporary cure to get Windows back
(1) Restore Windows MBR to the internal disk. Task B1 or B2 of my last signature refers.
(2) Use another Live CD that you can boot Windows with. Details in this thread