click on the "periodic table" button, at the far left of the grey window:
then in the periodic table that comes up click on the "oxygen" atom, then at the bottom of the window select the bonding option for two individual single bonds
goto the moluecule builder window (purple one) and click in the center
each time you click in the builder window you will create another moleucle of water
however at the moment we just want one so use the Edit tab (top line in the grey window) to remove the waters just added, to leave a single water
if for some reason you need to start fresh, closing the existing purple window will discard that molecule, then you can use the File tab to make a new molecule window
