Think I found answer. http://support.mozilla.com/en-US/questions/795204#answer-149957

That's it. Thanks! The text of your link is correct, but on my browser, when I click the link, it takes me to example.com or something. I'll repost. http://support.mozilla.com/en-US/questions/795204#answer-149957

The Firefox Button is off by default on XP, and possibly on some Macs. If you turn off the file menu you will see it use

• press keyboard keys Alt then in turn press V, T, M

Your bookmarks toolbar may also be off by default, and the bookmarks library option is re-worded but available from the firefox button. The alt key; keyboard shortcut will temporarily display the menu toolbar even whilst the firefox button is displaying.

Another change is save tabs on exit request is probably off, but even if the option does not request you to choose the restore session option will display the tabs. (option to display request on closing may be changed from preferences by using about:config).

I also installed FireFox 4 on Windows XP. Though I have a Firefox botton I don't have an app tab toolbar... just regular large tabs.... also do not have the new tab (plus sign) tab. Please help