Internet Explorer, or firefox both will offer to make themselves the default browser, and there may be some actions that are not possible or very dificult in firefox. I do not recall Windows itself preventing me from using firefox, other than because of firewall action. Possibly now security settings or software is blocking firefox downloads on your machine. When you do download firefox you may then discover it is blocked from running the installer, until you revise security settings. See these articles * [[unable to download or save files]] <-- clickable link (blue) * firefox [[software update failed]] *[[firewalls]]