If you are talking about the person who invented the Windows OS then yes it is Bill Gates as everybody is well aware of.
But if I take your question in a second way, I would answer none of the above.
The name of the OS invented by Bill Gates was first supposed to be named as Interface Manager. But then the head of the marketing of Microsoft , Rowland Hanson , suggested the name to be Windows.
So, the answer purely depends on how I take the question.