Fix a Broken Desktop GUI

I've fixed the problem. According to answer #1 at Ubuntu 12.04 - default Radeon driver does not work at all there were some missing drivers.To get hardware acceleration (tested on 12.04 Precise Pangolin), you need to add four more packages:After installing them, the desktop successfully completed initialization on my nVidia display (which has been plugged in all along). I suppose that was the "Magic" mentioned above. Both devices show up in lspci but I have not yet tried out two monitors. Moreover CTRL-ALT-F1 no longer opens a terminal so I can't say everything is perfect yet.

I've been running 12.04 on a NVidia GPU. I attempted to install ATI's proprietary catalyst drivers and a second GPU. Now the X-desktop will not start.

How do I refresh the borked desktop?

Can NVidia and ATI's HD series coexist?

"Will not start" may be a misnomer. The background comes up but the (taskbar?) on the left doesn't come up and the icons on the desktop can't be clicked. After a timeout I get a password request but then the desktop no longer shows.

I found a message from modem-manager trying to start saying it can't find /var/run/dbus/system_bus_socket. That may or may not be helpful

lspci: 03:00.0 VGA compatible controller 0300: NVIDIA Corporation GK106 GeForce GTX 650 Ti 10de:11c6 (rev a1) Subsystem: eVga.com. Corp. Device 3842:3650 Kernel driver in use: nvidia Kernel modules: nvidia_319_updates, nvidia_304, nvidia_304_updates, nouveau, ? nvidiafb 03:00.1 Audio device 0403: NVIDIA Corporation GK106 HDMI Audio Controller 10de:0e0b (rev a1) Subsystem: eVga.com. Corp. Device 3842:3650 06:00.0 VGA compatible controller 0300: Advanced Micro Devices, Inc. AMD/ATI Cedar Radeon HD 5000/6000/7350/8350 Series 1002:68f9 Subsystem: Hightech Information System Ltd. Device 1787:2291 Kernel modules: radeon 06:00.1 Audio device 0403: Advanced Micro Devices, Inc. AMD/ATI Cedar HDMI Audio Radeon HD 5400/6300 Series 1002:aa68 Subsystem: Hightech Information System Ltd. Device 1787:aa68 Kernel driver in use: snd_hda_intel