After upgrade to 12.04 every time I boot the PC and after passing the DELL screenshot I only see vertical black and white line that stay like that until the login screen loads. Then after login I don't have network connection. Enable Networking is ticked, but Wired Network and device not ready is grayed. The card and cable work (That's how I downloaded and upgraded) the all the rest of devices at home have internet access. What is not configured or has to be changed. I'm a Windows person, but I always like to have this old PC ready just in case.
I read some other post with the same problem and it doesn't look like it is resolved. I read some problems with NetworkManager not handling interfaces correctly for some reason. Someone state that after uninstalling NetworkManager got his connection back. I tried this method with no success.
Under System Settings > Network > It shows Wired cable unplugged (Is actually plugged and with network activity), and the options button is grayed.