Just for whoever is interested in some background knowledge about why out-of-focus pictures cannot be restored or otherwise "sharpened":
Whatever you want to take a picture of is some materia reflecting light. These light-rays are bundled in the camera to point to one single point in the camera (just like using a big lens to bundle sun-rays on some paper to make fire

If the lenses inside the camera are not adjusted properly, the picture gets out of focus, thus the light-rays do not just light one single point but several points at once and overlap each other. Consequence is a single line for example will be shown as a blurred line, but in addition the surrounding parts will also light the line itself. You can sure imagine the result: Details you need to see an image sharp are simply lost or faded.
Hope this helps to see the reason behind...
Patrick