Select Stand by my computer radio button if you want Sleep key to act as usual.
If you want Windows to ask you what to do when you press Sleep key, select Ask me what to do radio button.
To block Sleep key completly, select Do nothing radio button.

You can make I Hate This Key to block Sleep key completly, but enable it when some modifier key pressed along with Sleep key.
Select Act as usually if I hold these keys while pressing power keys check box and then select appropriate check boxes for modifier keys.