TLB not in Toolbars list

If you are using Windows XP Pro then you can use gpedit.msc for this.
Open gpedit.msc and open User Configuration->Administrative Templates->Desktop.
There are too many settings you can try all. But some is useful for your case:
Prohibit adjusting desktop toolbars
Prevent adding, dragging, dropping and closing the Taskbar's toolbars

Other values are on User Configuration->Administrative Templates->Start Menu and Taskbar:
Do not display any custom toolbars in the taskbar

Note sometimes the settings is not configured but can be turnden on by some tweaking software so it it useful to set settings into "Disabled" and the into "Not configured".