I got a question for you: The name was changed from Saxe-Coburg and Gotha to the English Windsor (from "Windsor Castle") in 1917 because of anti-German sentiment in the British Empire during World War I. There have been four British monarchs of the house of Windsor to date: three kings and the present queen, Elizabeth II. During the reign of the Windsors, major changes took place in British society. The British Empire participated in the First and Second World Wars, ending up on the winning side both times, but subsequently lost its status as a superpower during decolonisation. Much of Ireland broke with the United Kingdom and the remnants of the Empire became the Commonwealth of Nations.

Based on this passage, when did the royal family change to windsor?
Let's think first:
To answer the question, consider the following: The name was changed from Saxe-Coburg and Gotha to the English Windsor (from "Windsor Castle") in 1917 because of anti-German sentiment in the British Empire during World War I.
Therefore, the answer is 1917.