Im guessing that he wants to disable the navigation pane. If you want to do that, click the "Organize" option, "Layout" and then un-tick the "Navigation Pane" item.
To install 64bit windows, you need to have the 64bit windows disc (which should be provided along with the 32bit disc in a retail version). And as long as you make sure that 64bit drivers are available for your hardware, you should be fine! Regarding benefit, you'll only be able to see any...