When you start typing in Firefox 3's Smart Location bar (Support.Mozilla.com), a dropdown list of pages from your history and bookmarks that match what you've typed will be shown. If you would rather not have Firefox display this list, follow the instructions in this article.
If you would rather not have Firefox include bookmarks in the list list of page titles and web addresses, follow these instructions:
Create a file called userChrome.css in the Firefox profile folder's chrome sub-folder (e.g. C:\Documents and Settings\Your user name\Application Data\Mozilla\Firefox\Profiles\xxxxxx.yyy\chrome on Windows XP. See How to find your profile (Support.Mozilla.com).
Inside userChrome.css, put this code:
If you would rather have Firefox use a text-only list of web addresses instead of a list of page titles and web addresses, install:
If you would rather not have Firefox display autocomplete results at all. This method does not work on Mac.
Now when you type in the Location bar, no list of results will be shown.