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Before troubleshooting a Linux machine, it's helpful to know a bit about it. The term "Linux" just refers to the operating system kernel, which is basically just the "core" program that all of the other programs go through for resource management. When talking about the entire operating system, it's helpful include the distribution that you're using. A Linux distribution is the kernel + all of the other files and programs that the computer needs to run, and many distributions have a "stock" set of software (word processor, web browser, etc...) that are installed by default.
Distributions typically have a tag somewhere that will tell you what distribution it is. Common distributions are: Debian, Ubuntu, Gentoo, Slackware, PCLinuxOS, RedHat/Fedora, CentOS, ArchLinux, SuSE, and Mandriva.
It's also helpful to know what desktop you're running, which can be a bit trickier to a new-comer. The two main desktops that see quite a bit of action for new comers are KDE and Gnome. KDE typically has a bit of a "Windows-flair" to it, with the "start menu" being in the bottom left corner and a "task bar" that runs across the bottom of the screen (default, but they can be moved around). The "start menu" icon is usually a distribution-specific icon, though sometimes it's a gear with a "K" in it. Gnome's default (depending on what distribution of Linux you're using) has a bar (panel) across the top and bottom of the screen, usually with the word "Applications" in the top left corner.
While troubleshooting a Linux machine without knowledge of what specific desktop or distribution is possible, it's usually many times easier given that information.
Last edited by rocket357; 05-05-2008 at 11:33 PM.