Just because you say that Apple ripped off Xerox doesn't make it true. Anyone familiar with the story knows that Apple was GIVEN access to the facility. More importantly, Xerox made a conscious decision NOT to do anything with GUI. Finally, Xerox only had "ideas" which were in a very very raw format. Under Jobs' direction, Apple employees literally spent years making it work.
Comparing Apple's use of Xerox's ideas / facility to the blatent theft by Windows of the things that Apple developed is like saying that Henry Ford stole the idea for the automobile because he used wheels which were around for thousands of years. My point is that "new ideas" are obviously built upon older ideas. The difference between "stealing" an idea versus building upon existing knowledge has more to do with whether anyone was ever planning to actually create something. Xerox decided not to and Apple was GIVEN an opportunity by Xerox to make it happen. With Windows, Microsoft actually just copied what Apple did---and they did a pretty terrible job of copying them BTW.