I am not sure about this answer but I noticed no one else had tried so
here goes. You can either hit the "X" button or go to VIEW...TASK PANE
and deselect it.If you are talking about completely disabling all help
panes from ever appearing,then do the following...

On the Help menu, click Microsoft Excel Help
Under See also in the task pane, click Online Content Settings.
Verify that the Show Template Help Automatically Checkbox is
Deselected.

Other than that I dont know anything else to try other than the Help
files...
Hope that helped