1. Type about:config in the browser’s location bar, and press Enter.
2. If a warning displays, click I'll be careful, I promise!
3. Search for the following preferences and set them to the recommended value by double-clicking the preference name. Changes take effect immediately.
4. Enable tab focus on text fields, form elements, and links by setting this accessibility preference.PreferenceRecommended ValueDefault Valueaccessibility.tabfocus71
5. Change how the browser retains common resources across requests by setting these caching preferences.PreferenceRecommended ValueDefault Valuebrowser.cache.check_doc_frequency33browser.cache.disk.capacity50,000 or more; increase to use more hard disk space50,000browser.cache.disk.enableTrueTruebrowser.cache.disk_cache_sslTrueFalsebrowser.cache.memory.enableTrueTrueNote You can set some of these preferences by clicking Tools | Options in the Firefox browser. Refer to Firefox Help for details.