Hello Hellen. If you're just getting a new CPU, you shouldn't need to worry about backing up your information, since you don't need to format your hard drive to change the CPU. However, and I don't mean to insult you in any way, so please forgive me for my assumption, if you're referring to the computer (the tower itself, with the drives, boards and all that) as a "CPU", hopefully this support article is what you need: http://support.mozilla.com/en-US/kb/Backing+up+your+information The main thing to remember is that you don't need to just back up your bookmarks. You can port your ''whole'' Firefox experience (that includes passwords, history, cache, settings, add-ons, bookmarks, home pages, absolutely everything) from computer to computer by just copying your profile folder around. It's a brilliant thing that many people don't know, and often people will start all over again, which is totally unnecessary and definitely a big shame. I hope this helps.