Creating a new default profile
- This article was written for Firefox but also applies to Thunderbird and to 模板:SeaMonkey 2.0 and above.
Many problems with Firefox can be solved by creating a new Firefox profile. In rare cases, using the Profile Manager is not successful because the newly-created profile disappears from the Profile Manager, even though the profile folder itself is created. . To get around this problem, or if you just want to start fresh, you can force Firefox to create a new default Firefox profile by exiting Firefox (if open) and then deleting or renaming the profiles.ini file located in the default profile path.
Warning: This will cause the Firefox Profile Manager to lose track of all existing profiles and only a single "default" profile will be listed, pointing to a new default profile folder that does not contain any of the profile data or settings stored in your existing profile. To add back an existing profile to the Profile Manager, read Recovering a missing profile.
When you delete the profiles.ini file you should also rename the existing default profile folder at the same time (or remove it to a backup location), so that you don't confuse it with the new default profile folder that will be created. When you next start Firefox, it will open with a new default profile, just as though you installed Firefox for the first time. Your existing Firefox user profile data, which includes bookmarks, passwords, cookies, preference settings and added extensions, will no longer appear in the new profile but you can transfer the data from the old profile folder to the new default profile folder.
For example, on Windows XP, a "default" Firefox profile folder would be located here ("xxxxxxxx" represents 8 random characters):
C:\Documents and Settings\<user name>\Application Data\Mozilla\Firefox\Profiles\xxxxxxxx.default
The "Application Data" folder is normally hidden; to open it, click the "Start" button to open the Windows Start Menu, then select "Run", type in %APPDATA% and click "OK". The "Application Data" folder will then open. Double-click the "Mozilla" folder, then double-click the "Firefox" folder. You will see the "Profiles" folder and some files. Rename the "profiles.ini" file, for example, rename it "profiles.iniOLD". Now open the "Profiles" folder and either remove the existing profile folder or rename it (for example, rename it "xxxxxxxx.defaultOLD"). When you next reopen Firefox, a new "xxxxxxxx.default" folder (with a different string of random characters) will be created and and the new profiles.ini file that is also created will point to that new folder.
Caution: Do not simply delete the profile folder that contains your user data, as doing so can result in a "profile in use" or "already running" message when you next attempt to run Firefox (bug 278860).