Do you have access to the Firefox Profile Folder of that broken installation? * https://support.mozilla.com/kb/Profiles#How_to_find_your_profile * http://kb.mozillazine.org/Profile_folder_-_Firefox The "Application Data" folder in XP/Win2K and the "AppData" folder in Vista/Windows 7 are hidden folders. * Use %APPDATA% in the "File name" field or make sure that you see hidden folders * http://kb.mozillazine.org/Show_hidden_files_and_folders * Go to: Control Panel > Folder Options > "View" tab, and under "Hidden files and folders", select "Show hidden files and folders" * To see all file extensions uncheck the box "Hide extensions for known file types" * XP: C:\Documents and Settings\<user>\Application Data\Mozilla\Firefox\Profiles\<profile>\