I just did a fresh install of ubuntu 12.04 on my PC (Dell precision 370) but the video is not working as it should. Problems: When I log in to unity 3D I get a transparent bar (where the firefox, libre office, etc icons are) but I can see the tooltips when I put my mouse over where the icons are, I can see the top toolbar with no problem and I see just white on the rest of the desktop! When I log in using unity 2D I see the left bar cut in half (so I can't see the trash icon that is at the botton), the toolbar at the top shows OK and the desktop show OK but with some apps. For example, if I open a terminal and maximize it, it will only show just where the left toolbar "cuts". But if I open firefox it will open fine. Config: My PC comes with a nvidia quadro nvs 280 and I see that by default ubuntu is using the nouveau driver. Workarounds tried: I tried uninstalling the nouveau driver and the desktop works fine but I can use only unity 2D. I tried installing the nvidia-173 drivers using synaptic but I get "Could not apply changes! Fix broken packages first". I go to "Edit - Fix Broken packages" and I get the error: "E: Unable to correct problem, you have held broken packages.E: Error, PkgProblemResolver::Resolve generated breakes, this may be caused by held packages.E:Unable to correct dependencies" Output of lspci: 01:00.0 VGA compatible controller: NVIDIA Corporation NV37GL [Quadro PCI-E Series] (rev a2) Any idea so as to what I should do? Thanks in advance for any help. PS: Ah, the nvidia-173 driver was working fine on ubuntu 10.04.