I have a hardee plank house. My windows have a piece of aluminum over them (for water protection). Anyone know what this item is called?

Various terms, head flashing, (ridge) cap flashing, drip cap...

It was a 'Drip Cap'. Thanks you all for your help and time.

The nearest that I can get to what you are searching for is 'a drip stone', but that applies to a stone moulding (which does the same job as your metal piece). What you have could be called (in England, anyway) a drip moulding, or maybe a rain deflector.

Hardie Plank fiber cement siding is very strong. I don't know why the installer or previous owner put aluminum over the windows. Maybe the previous owner could answer this.