On a Linux or Mac system, you must have superuser privileges to perform a PostgreSQL installation. To perform an installation on a Windows system, you must have administrator privileges.If you are installing PostgreSQL into a Windows system that is configured with User Account Control (UAC) enabled, you can assume sufficient privileges to invoke the graphical installer by right clicking on the name of the installer and selecting Run as administrator from the context menu. If prompted, enter an administrator password to continue.You must install xterm, konsole, or gnome-terminal before executing any console-based program installed by the PostgreSQL installer.Be sure to apply Windows operating system updates before invoking the PostgreSQL installer. If (during the installation process) the installer encounters errors, exit the installation, and ensure that your version of Windows is up-to-date before restarting the installer.PostgreSQL installation on Mac OS X differs slightly from other platforms as the distribution is in a different format, and some additional configuration may be required.The Mac OS X installer is an App Bundle (a set of files and directories in a prescribed format). The installer is available as a disk image (.dmg) file from the website or as an archive (.zip) from Stack Builder. To extract the installer, simply mount the disk image and copy the installer to the desired location, or run it directly from the disk image.By default, Mac OS X ships with shared memory settings that are too low for running PostgreSQL. The installer will detect this, and if possible, reconfigure shared memory and then prompt you to reboot the system and rerun the PostgreSQL installer. For more information, please see the README file in the distribution disk image.