losting every thing after edit profile

Wow, I'm sorry to hear about your experience. Firefox stores your data in a profile folder. If Firefox deleted your main profile, I'm surprised it would do that while you are using it. Especially if there's no big warning not to. Someone needs to look at that. Unfortunately, I think deleting a profile through Firefox doesn't move the profile folder to the Recycle bin, so there probably is not an easy way to recover. Were you using Firefox Sync through a Mozilla account? Signing in to the same account should recover bookmarks, passwords, and some history. Open tabs would be available for a while in the Synced tabs sidebar and you could open them in the new profile. If you were not using Sync, you probably need to use a backup (for example, if you had Windows or other software making backups). You also could try Recuva, which is an "undelete" utility: https://www.ccleaner.com/recuva The area to explorer is in a hidden folder, so you may want to set Window to display hidden files and folders. C:\Users\<username>\AppData\Roaming\Mozilla\Firefox If you are able to find these files in a backup or in recovered data, we could explain how to try to recover them: * logins.json + key4.db * sessionstore.jsonlz4 * sessionstore-backups\recovery.jsonlz4 * sessionstore-backups\recovery.baklz4 * sessionstore-backups\previous.jsonlz4 More info on profile folder files: [[Profiles - Where Firefox stores your bookmarks, passwords and other user data]]