Troubleshooting X

Sometimes new users, expecting a graphical environment after installing Ubuntu, end up at a black screen with some white text that has a login prompt. When they log in, they see this:

I haven't experienced this myself, but I've seen it happen to other new users, either because they accidentally did a server install... or Ubuntu just did something funky.

Do you have a graphical environment installed?
The first step requires you to have a software repository. In most cases, if you're connected to the internet, the commands given will use your internet connection. If you don't have an internet connection but do have the Ubuntu Alternate Installer CD, insert it in your drive and type

This will add the CD as a software package source since you can't get packages from the internet.

To make sure you have a graphical environment installed:

If you didn't already have it installed, you'll notice Ubuntu downloading and installing a whole bunch of packages, either from the internet or from your CD.

If you did have it installed, you'll simply be told ubuntu-desktop is already the newest version.

Run the graphical environment
Now that we have it installed, let's use it:

This should get you to a graphical login screen. If it says it's starting the GNOME Display Manager but after ten seconds or so... it doesn't actually appear to start, try pressing Control-Alt-F7, which should get you to the graphical login screen.

You have a graphical environment, but it won't show the way I want it to
Well, what if you get a graphical environment you can't see? It's a black screen but your monitor's working, or you get that the monitor signal is out of range, or the screen resolution is just too low for your tastes.

Well, then press Control-Alt-F1 and try this:

This will pop up a text-based graphical "wizard" that will ask you questions about your keyboard, your mouse, your graphics card, and your monitor. Answer the questions as best you can. If you don't know the answer to a question, just go with the default and press Enter.

When you're done, press Control-Alt-F7 to get back to graphical mode and then Control-Alt-Backspace to reset the X server (so your changes can take effect).

Next steps
In a lot of cases, these steps will get you all straightened out. If not (for example, if you are still unable to reach your optimum screen resolution), look here for other possible solutions.

Other variations
If you're using Kubuntu, it's the same deal--just replace ubuntu-desktop with kubuntu-desktop and replace

If you're using Xubuntu, it's the same deal--just replace ubuntu-desktop with xubuntu-desktop.