Since I can administer Firefox by means of an ADM?Thanks

You can centrally manage Firefox using FrontMotion's FireFox Community Edition.This free downloadable package in multiple languages includes: A Firefox MSI installation package to install Firefox centrally using Group Policies.KnowledgeBase article 816102provides more information if you need it. Firefox Administrative Templates(*.adm file), to centrally manage Firefox using Group Policies.KnowledgeBase article 816662 provides more information and recommendations for this step.