If you have installed Mathematica in a location where multiple users can run it (for example, on a file server or multi-user machine), then you can set up systemwide defaults for the Mathematica front end and kernel. This is ideal for setting up Mathematica for use in computer labs and classrooms. If you share the directory $BaseDirectory across the network, these defaults will also take effect on local installations that use the shared $BaseDirectory.
In the pathnames that follow, replace the variables $BaseDirectory and $UserBaseDirectory with the appropriate directories for your system. To find their locations on your system, evaluate the command $BaseDirectory (or $UserBaseDirectory) in a Mathematica notebook.
These settings will now be used by the front end unless overridden by the local init.m file stored in the user's $UserBaseDirectory\FrontEnd directory.
2. Add any Mathematica commands that should be evaluated on startup. For example, you may want to add a function definition or display a message at startup. Enter all the commands in the same cell, separating commands with semicolons.
If you have created systemwide defaults you want to carry over to new local installations, you can add lines to an installation script to copy preconfigured init.m files as part of a new installation. For information about installation scripts, see "Installing Mathematica". To copy systemwide defaults, add a line to the script similar to the line that copies the mathpass file.