I need to install the ATI proprietary driver on my laptop (Asus K54HR) as I use it for gaming. My problem is, it doesn't matter what I try, I have always the same result black screen and I have to reinstall ubuntu. It works fine with external monitors but not with the laptop screen. I use Ubuntu 14.04 in dual boot with windows 7 both 64bit. I tested it with 12.04 64 bit too. My graphic card is Radeon HD 7470M Seymour series. What can I do?