firefox.exe -P

Do you recall what Firefox was doing before this problem started? For example, Firefox might lose track of your profile folder if it was interrupted during the Refresh process. Knowing the last thing Firefox was doing would be helpful in getting some or all of your data/settings back. IMPORTANT: Do not use the Windows "system restore" feature unless all else fails because it can cause permanent data loss. To get Firefox back up and running, the first step is: '''Create a new Firefox profile''' A new profile will have your system-installed plugins (e.g., Flash) and extensions (e.g., security suite toolbars), but no themes, other extensions, or other customizations. It also should have completely fresh settings databases and a fresh cache folder. Exit Firefox if applicable. Start up the Profile Manager from the Run dialog or system search box by typing or pasting the following and pressing Enter to run it: firefox.exe -P This should display the Profile Manager dialog. ''Don't delete anything here!'' Any time you want to switch profiles, exit Firefox and return to this dialog. Click the Create Profile button, assign a name like June2016, and skip the option to relocate the profile folder. After creating the profile, select it and start Firefox in that profile. Will Firefox start? Good. Next we can search for your data.

'''http://kb.mozillazine.org/Profile_folder_-_Firefox#Navigating_to_the_profile_folder''' '''https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles''' '''https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible'''