IECUSTOMIZER
Hi,
There is a limit to the number of toolbars or explorer bars you can install.. 16 of each I think. If the toolbar/explorer bar has been installed and is available to the browser then it should appear in either the View>Toolbars or the View>Explorer Bars menu.
It may have been installed as a disabled Addon (I think this was standard for some installs during the IE7 development). Check your Tools>Manage Addons menu to see if it has been disabled by default, re-enable the toolbar.
IMHO, IEWatch is probably the only debugging tool you will need. 5*.
Regards.