I have Ubuntu 12.04 installed alongside Windows 8 on a HP Pavilion g7 1303 (x64). I ran the update manager and selected everything and updated. Then I restarted the computer and when it comes to the login screen, I entered my password. Then the screen went black (and some text which I can't read because it disappears too fast.) for a second (or less)and then opens the login screen again. Then I entered a wrong password and it says invalid password so the problem isn't that I forgot my password. I tried using recovery mode and changing my password from the command line and then I logged in again with the new password and there was the same screen. I tried reinstalling Ubuntu and updating again and I got the same error. Please help!