I have confirmed these directions worked on Windows 7 x64 using SCCM 2007, Mozilla Firefox Version 28.

1. Download the latest Mozilla Firefox download from: http://www.mozilla.org/en-US/firefox/all/
   
   
2. Create a folder to put all of the install files in. I created mine on my desktop and named it Firefox.
   
   
3. Open notepad and paste the following:
   
   

   [XRE]
   EnableProfileMigrator=False

   
   Save it as 'override.ini' in the folder you created in step 2.
   The override.ini file disables the Import/Migration wizard that comes up on the Firefox first run.
   
   
4. Open notepad and paste the following:
   
   

   pref("general.config.obscure_value", 0);
   pref("general.config.filename", "mozilla.cfg");

   
   Save this as 'local-settings.js' in the folder you created in step 2.
   
   
5. Open notepad and paste the following:
   
   

   //Firefox Default Settings
   
   // set Firefox Default homepage
   pref("browser.startup.homepage","ENTER HOMEPAGE HERE");
   
   // disable default browser check
   pref("browser.shell.checkDefaultBrowser", false);
   pref("browser.startup.homepage_override.mstone", "ignore");
   
   // disables the 'know your rights' button from displaying on first run 
   pref("browser.rights.3.shown", true);
   
   // disables the request to send performance data from displaying
   pref("toolkit.telemetry.prompted", 2);
   pref("toolkit.telemetry.rejected", true);

   
   Save this as 'mozilla.cfg' in the folder you created in step 2.
   
   This above code allows the automatic updating using the background updating service. If you want to disable automatic updating, add this to the code above:
   
   

   // disable application updates
   pref("app.update.enabled", false)

6. Open notepad and paste the following:
   
   

   [Install]
   
   QuickLaunchShortcut=false
   DesktopShortcut=false

   
   Save this as 'configuration.ini' in the folder you created in step 2.
   This disables the Quicklaunch shortcut and desktop shortcuts. Set them to 'true' if you want to enable the shortcuts.
   
   There is more you can add to the configuration.ini, which you can find here:
   https://wiki.mozilla.org/Installer:Command_Line_Arguments
   
   
7. Open notepad one last time, and paste the following:
   


   @ECHO OFF
   
   "%~dp0Firefox Setup 28.0.exe" /INI="%~dp0configuration.ini"
   
   if exist "%ProgramFiles(x86)%\Mozilla Firefox\" copy /Y "%~dp0override.ini" "%ProgramFiles(x86)%\Mozilla Firefox"
   if exist "%ProgramFiles(x86)%\Mozilla Firefox\" copy /Y "%~dp0override.ini" "%ProgramFiles(x86)%\Mozilla Firefox\browser\"
   if exist "%ProgramFiles(x86)%\Mozilla Firefox\" copy /Y "%~dp0mozilla.cfg" "%ProgramFiles(x86)%\Mozilla Firefox\"
   if exist "%ProgramFiles(x86)%\Mozilla Firefox\" copy /Y "%~dp0local-settings.js" "%ProgramFiles(x86)%\Mozilla Firefox\defaults\pref"
   
   EXIT

   
   Save this as 'Install.cmd' to the folder you create in step 2
   
   
8. Upload to SCCM and set 'Install.cmd' as the command line, set to Hidden, test!
   If not using in SCCM, just run Install.cmd with administrator rights and it should install all the same.

Sources:
http://www.mockbox.net/configmgr-sccm/174-install-and-configure-firefox-silently
https://wiki.mozilla.org/Installer:Command_Line_Arguments
https://wiki.mozilla.org/Deployment:Deploying_Firefox