I'm new to Ubuntu and just installed 14.04.3 on a 2008-vintage HP desktop with an Nvidia GeForce 7300 GS video card. Upon rebooting after the install, I got a black screen.
Assuming a video driver issue, I searched and found the following procedure (I also found the major driver number, 304 for my card): sudo add-apt-repository ppa:xorg-edgers/ppa -y sudo apt-get update sudo apt-get install nvidia-304
Now it boots to a wallpaper screen, but all the icons on the left edge of the screen are blank. Eventually, "Ubuntu desktop" is displayed at the top left of the screen, and the current time at the top right. If I mouse around, I can get the gear at the top right corner, but I can't always get into the System Settings from the drop-down menu. In fact, sometimes the menu won't appear and the mouse cursor freezes.
How do I fix this?