Hello Greg.

You can uninstall unwanted extensions by going into Tools > Add-ons > Extensions.

You can select which toolbars to see by going into View > Toolbars. Also, you can reset your interface by going into View > Toolbars > Customize... > Restore default set.

See, I removed that toolbar with "view" and "tools" and I don't know how to bring it back

If it's listed in View > Tools, simply click its entry to add it to the interface. If it's not listed, it probably was an extension that is no longer installed/enabled. You'll have to use the add-ons manager (Tools > Add-ons > Extensions) to see if it's installed but disabled (simply enable it in that case) or uninstalled (you'll have to install it again). If it is installed and enabled and it's still not showing, contact its author for support.

In Firefox 3.6 on Windows you can hide the menu bar via "View > Toolbars" or via the right click context menu on a toolbar. Press and hold the Alt key down to bring up the menu bar. Go to "View > Toolbars" or right-click the menu bar or press Alt+V T to select which toolbars to show or hide.

See also Restore the Menu bar in Firefox

Thanks guys, it's fixed now