When you say "Computer", do you mean a common web page on the intranet (local network), or opening each computer's files as a home page?

Use a mozilla.cfg file in the Firefox program folder to lock prefs or specify default values for all users.

Place a file local-settings.js in the defaults\pref folder where you also find the file channel-prefs.js to specify using mozilla.cfg.

pref("general.config.filename", "mozilla.cfg");
pref("general.config.obscure_value", 0); // use this to disable the byte-shift

See:

• http://kb.mozillazine.org/Locking_preferences

You can use these functions in mozilla.cfg:

defaultPref();  // set new default value
pref();         // set pref, but allow changes in current session
lockPref();     // lock pref, disallow changes

pref("browser.startup.homepage", "<your preferred home page>");