Internet Explorer stores toolbar names in Windows registry and sometimes this list gets damaged.With this link you can delete the value of this registry key so that IE can rebuild the toolbar.

This utility may fix this problem but it may reset any customization you have done to IE toolbars.

If you can't succeed to reset the toolbar we suggest to uninstall and then reinstall Internet Explorer and all third party toolbars you use.

You can download Internet Explorer from here.