Firefox does not save the bookmarks in the favorites folder, the files in the favorites folder are likely to be those from Internet Explorer. Firefox saves bookmarks in a file called places.sqlite in your [[profiles|profile folder]]. Did you make any backups before installing Windows 7? To see if there is a copy of the old Firefox bookmarks file anywhere on the computer, first set Windows 7 to [http://windows.microsoft.com/en-US/windows7/Show-hidden-files show hidden files], then search all folders on the computer for a file called places.sqlite You should have a file called places.sqlite in your current [[profiles|profile folder]]. This one does not contain your old bookmarks. Do you have any more places.sqlite files? If you do have a version stored elsewhere, you can copy that file into your current profile folder, replacing the places.sqlite file that is already there. The places.sqlite file stores bookmarks and history, so replacing that file will give you the bookmarks and history from the alternate file.