Quick launch comes with Internet Explorer 4.0, SP1. You will have to install IE 4.0 in order to have quick lanch in NT. If you upgrade from an IE older than ver 4.0 to IE 5.0 or later you will not be able to see quick launch, as far as I know.
Now, on your systems which don't have IE 5.5, install IE 4.0 first and then upgrade to IE 5.5, if necessary.
And, the systems which already have IE 5.5, uninstall IE 5.5 and repeat the process I mentioned above.
The keyword for quick launch is IE 4.0.Hope it helps.
Mubashir