Sorry to hear about that. Something strange is happening with Windows 7 users at the moment. I suggest waiting on the update to Firefox 53, which is easier if you have it set to "Check for updates, but let me choose whether to install them" on the Options page. [[Advanced panel - Accessibility, browsing, network, updates, and other advanced settings in Firefox]] If you get an update message for an "esr" version and you are using the standard release, close it.