MediaWiki installs itself using an interactive, web-based installation script. Before you can run this script, you need to do a couple of things. First, ensure that you have installed prerequisites (Apache/IIS, MySQL4 or later and PHP5). Then you must acquire the MediaWiki software package and upload the MediaWiki software to your server. You may also have to create a new database for your wiki. If necessary, create an account on your web server by following the instructions at Manual:Installation/Creating system accounts.
MediaWiki can be difficult to install for the average computer user who does not have experience with Apache, PHP and MySQL. Most users who wish to use wiki software may benefit from using a free wiki host (see a list of wiki hosts on Wikibooks) or via a software appliance.
MediaWiki needs to be able to write to the MediaWiki-folder/config directory when it runs its installation script. If you haven’t done so already, you need to change the permission settings for the config subdirectory so that it is writable by the webserver. If you are using FileZilla, right-click on the config directory, select “attributes…”, and check “Write” under “Owner”. If it prompts you for a number instead or if you are using a command-line interface, use 755 (Use 777 on Linux except for RedHat Linux). Alternately, you may be able to change permissions using a “control panel” provided by your web host.
Depending on the server configuration, in some cases you have to check all boxes (777) in FileZilla, to be able to run the install-script of MediaWiki.
On Unix or Linux, if you have admin rights, you can run the command chmod 755 config in your wiki directory.