I just installed Ubuntu 12.04 on my computer. At first it worked just fine, but when i started updating the system just "updated" the screen, and then freezed. Same thing happens when I log in. Any tip?
I had a lot of problem when updated to 12.04.
What i've done was in a console ( ctr + alt + f1 ) to uninstall the packages xserver-xorg, ubuntu-desktop (and fglrx packages because i have an ati)
sudo apt-get remove --purge xserver-xorg ubuntu-desktop
After doing this you may have uninstalled some usufull packages like gnome. Before uninstall check the packages that apt-get uninstalled to manually do that when you reinstall again the packages.
sudo apt-get install xserver-xorg ubuntu-desktop
--------- [init] DO YOU HAVE AN ATI?----------------
sudo apt-get remove --purge fglrx*
Then try to install your graphic card drivers property. If you have an ati:
http://support.amd.com/us/gpudownload/Pages/index.aspx (download it before you uninstall these packages)
I also recommend do check this post: X doesn't start after Upgrade from 11.10 to 12.04
--------- [END] DO YOU HAVE AN ATI?----------------
Before you try this you can also try to run the command:
apt-get install --reinstall xserver-xorg ubuntu-desktop