I'm worried about the phrase: After forcing the driver installation of the Galileo driver… I'd recommend you to do all the process again. As far as I know, the note in the instructions is referring to when you connect the Galileo Board, and Windows immediately tries to install the drivers automatically. At least for me, that was the only error that showed up.
Go ahead and try to re install the drivers from the Arduino-1.5.3 folder and let us know what were the results. Have a nice day!