Before we resort to a saved game, here is some advice that another forum member offered about the crane:
When extending the crane, I found I had to do this in small stages, eg. click the lever, let go, click again, let go until the crane has extended all the way to the open window. There are at least 4 parts of the crane to extend. Good luck.
Maybe give this a try, if you haven't already - and if you still need a saved game, please let us know.
