simply type, startx in the command prompt.
the command "display" brings up the ImageMagick program.
Enter this command as root: "apachectl start"
It's a command to start the X server for running Linux in graphical mode, if you have any of the desktop environments and/or window managers installed.
"Run Levels" in Linux are different startup or shutdown settings that can be used at any time to force Linux into a given state using the "init" command. Level 0 forces a total system shutdown. Level 1 switches to "maintanance mode" and only allows the system administrator to log in. This is about the same as Windows "safe mode with command prompt". Levels 2 and 5 can be defined differently, depending on what version of Linux you are using. Typically, one of these is set to start the graphical user interface, another to start only the command line, and so on. The exact results, again, always depends on what version of Linux is used. Level 6 forces the system to reboot. It should be helpful to note that runlevels are not in every Linux system. Systemd-based setups do not have runlevels. The closest they have are "targets," though these are not completely analogous to runlevels.
Chkconfig is a utility tool that is used in Linux operating systems to start or stop a program from automatically running when the system starts. You can also use the command to view or set up new services on your operating system.
after you have identified the service run the command # service (service name) stop #service (service name) start
To start the System Monitor from the terminal or run window, you can type "gnome-system-monitor" (without quotation marks, of course).
F9
Re-install the operating system or install Linux.
X11 is enabled and launched by default in most desktop distributions. If it is installed but not started automatically, you can usually start it with the startx command.
In DOS, just run "exit" command to return to GUI.In Redhat Enterprise Linux, run "startx" for GNome and "startkde" for KDE.