Note: anyone finding this post now, I’m probably not going to see your response if you ask for help here. If the fixes below don’t work for you, or you need help applying them, please see http://mozilla.com/support for help options including forums and live chat (IRC).
I understand how scary and angering it can be to install a new app and then bam, important info is gone. Fortunately this time, they’re not actually gone! Take a deep breath (I’d need one about now if this happened to me) and I’ll explain how to get them back.
Bookmarks missing after installing Firefox 2
Quite a number of people are reporting that after installing Firefox 2 their bookmarks are missing. This is a different issue and much easier to fix than the usual crash issue. The bookmarks are also NOT lost. In some cases the installer isn’t exiting existing Firefox processes properly and not updating some of the old files. This causes several odd issues including tabs not working properly, and for bookmarks to not show up. A bug has been filed, a permanent fix will be available ASAP. Bug 357922
There are two ways to fix this:
* Uninstall Firefox, delete the install folder (C:Program FilesMozilla Firefox by default) and install Firefox 2 again. Everything will be back to normal, including the bookmarks. This will not cause any loss of any other personal data. That data along with bookmarks are kept in the profile folder in Application Data.
* Install Firefox again using the custom install option and chose to install it to a new folder. Again, no loss of personal data as this installation will still detect and use your existing profiles.
Everyone has reported both of this fixes clear the issue right up and that no other issues are encountered.
Update: You shouldn’t have to delete the install folder for a reinstall to be effective. Uninstall Firefox 2, then make sure firefox.exe isn’t running in the task manager (be sure to check other users) and then install again. The files causing the problem should be overwritten.
To avoid this issue on installation
Until the bug is fixed you can absolutely avoid this problem by closing firefox before running the installer (check the processes tab in task manager), or by using the custom install and installing Firefox 2 to a new folder.
We are still working to narrow down exactly why this is happening to some users and not others. So far we’ve had several people install Firefox 2 with 126.96.36.199 running and they’re not hitting the issue. This might be caused by another issue that is preventing the firefox process from exiting, for example some extensions do this on occasion. I’ll be sure to update this blog, and the bug as more information becomes available. If you have experienced this issue yourself and would like to help narrow it down, comment here, or on the bug or come find us in #firefox on irc.mozilla.org