I'm surprised you have to do it through device manager - once the drivers were installed for me, it automatically installed them for a new board that was plugged in (so that if the IDE has been installed with the installer, it won't even need a manual installation step).
The clone boards with other serial adapter chips may be better behaved in this regard... Windows seems to be able to tell arduino boards apart, but it doesn't seem to be able to tell CH340G's apart.