I am trying to install Ubuntu on a Lenovo G500, CPU is Intel Core i3-3110M, 4GB RAM, and as you can guess, dual graphics: Intel HD 4000 for the basic stuff and AMD Radeon HD 8570 for the good stuff.

I went through the installation without problems, but when I try to boot the system fails: initially I get a message that the screen, graphics adapter and keyboard/mouse could not be automatically configured.

I have tried installing fglrx through APT and from AMD's proprietary drivers. I then installed XFCE as well.

Through some testing, I have realized that whenever I try to use X11, it gets stuck with the aforementioned message. I can then go into the commandline and delete the xorg.conf files from /etc/X11. After this, I am able to arrive to the logon screen.

When I try to log in everything freezes up (with the Unity interface). I successfully pass through the authentication, but then nothing happens. Occasionally there are some popups saying that there have been system errors and prompting me to report them, but nothing else. If I try to use an XFCE session, it works just fine. Why can I not access Unity?

In XFCE, I tried to install the Catalyst Control Center in order to deactivate the AMD card as I need the battery life. However, as soon as the packages are installed, it reverts to the error message (GUI could not be configured, the system is running in low graphics mode, blah blah blah).

What I noted today is that by running the command lspci I see the Intel GPU as a VGA adapter, while the AMD device is listed as a Screen Adapter (no VGA). Perhaps it has something to do with this.

If anyone has any idea or hint, it would be most appreciated.

Another thing is that I did this to another laptop with switchable graphics, a Samsung with Intel HD 3000 and AMD Radeon HD 8750, and it works perfectly fine. As soon as I installed the proprietary drivers, I was able to execute CCC and set it up to use the Intel VGA only.