Chapter 31. X Window System Configuration
During installation, the system's monitor, video card, and display settings are configured. To change any of these settings after installation, use the X Configuration Tool.
To start the X Configuration Tool, go to System (on the panel) => Administration => Display, or type the command system-config-display at a shell prompt (for example, in an XTerm or GNOME terminal). If the X Window System is not running, a small version of X is started to run the program.
After changing any of the settings, log out of the graphical desktop and log back in to enable the changes.