SAVING PREFERENCES :
Go to your Firefox profile folder in Windows Explorer. The default location is Documents and Settings > USERNAME > Application Data > Mozilla > Firefox > Profiles > cxhmjww8.default (this name is random)
The file you're looking for is prefs.js. Copy it to a USB stick or burn it to CD.
If you need to reinstall Firefox, drag your backup copy of prefs.js into this folder. You'll get a message asking if you want to replace the existing prefs.js file with your copied file -say yes, and you'll have restored your Firefox preferences the way you wanted them.
Of course there's no point backing up if you don't do it regularly - so be sure to update your saved prefs.js file when you tweak your Firefox settings.
SAVING BOOKMARKS :
To back up your Bookmarks,
- Open Firefox
- Go in Bookmarks -> Organize Bookmarks
- Go to Import and Backup -> Export HTML...
- Save it somewhere as a .html file and you're done.
SAVING PASSWORDS :
- Go to Documents and Settings > USERNAME > Application Data > Mozilla > Firefox > Profiles > cxhmjww8.default (this name is random)
- Backup the following files : key3.db, signons2.txt (if you're using FF 2.0+) OR signons3.txt (if you're using FF 3.0+). These files contain data regarding your saved passwords. After a reinstall, overwrite these files back to this folder.