If they were the same letter the computer would get confused and for that matter so would I. For external drives the letter assigned by the computer is not set in stone. So to copy one drive to the other you would select all the files on one (F
) right click and select copy. Then click on the second drive (G
) and in the empty area right click and select paste.
After the files are all copied you move the second drive to the other computer and plug it in. That computer will select a drive letter. Open Hoster, open Tools/Rebuild Database then set it to point to the external drive and rebuild.