Ok I have found with external drives that they miss a OS version. For me what I used on XP would not open with Win7 but will with Win10 Is pretty strange. See if will open on someone else s Win 7 and will save yourself a lot of trouble. I think that also has changed between versions.... 8.1 and up But https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data should be for Win 7 looking for this file I think places.sqlite The above url May help you. I think that also has changed between versions.... 8.1 and up below C:\Users\<Windows login/user name>\AppData\Roaming\Mozilla\Firefox\Profiles\<profile folder>. then a letters and numbers is the file looking for. Try someone's Win 7 Please let us know if this solved your issue or if need further assistance.