I had about 100 Bookmark Folders and 500 to 600 Bookmark sub-folders inside the Bookmark Folders on Firefox 3.6.17. When I signed off my Windows XP system on Thursday the Firefox home Page was fine. When I logged on to the Firefox Homepage the next day the page changed and I was unable to change it back, the "add Apps" had no effect and I could not customize the page. My home page is google com ig dell using Mozilla Firefox as my Browser so I called Dell to get help. The Dell technician played with it for about 1 1/2 hours and then decided Firefox was corrupted and he would have to load a new copy. He uninstalled the old 3.6.17 and installed 4.0. I specifically told him I had lots of Bookmarks and could not lose them. He assured me it would be No Problem. When I checked after he finished, I had lost all my bookmarks. The Dell Technician could not retrieve the Bookmarks and had to go to a Dell Datasafe Backup that I did. He could only retrieve a small portion of my Bookmarks. It will take me weeks to build these Bookmarks again. I can't believe these are all gone from my hard drive. Is there anything I can do to retrieve them and how can I prevent this in the future.