Which one is better?

Well the Asus is better if you go with an upgrade to a dedicated graphics card, but more to the point why is your friend not building his own PC? His money will carry him much further with a build-it-yourself option.
 
He can't. And he don't wan't to. I said him I can build it for him, but he said "Nah, it's easier to just buy prebuild"

 
Well if there is no changing his mind, then there is little you can do.

The HP has built in graphics which is no good, even for "low gaming".

The Acer you linked is not built out so I have no idea you he plans on optioning it, but I would bump the processor to at least an A8 and go with as much graphics as he can afford.