According to the Wikipedia article on Windows XP[0] > At PDC on July 13, 2000, Microsoft announced that Whistler would be released during the second half of 20

According to the Wikipedia article on Windows XP[0] > At PDC on July 13, 2000, Microsoft announced that Whistler would be released during the second half of 2001, and also unveiled the first preview build, 2250. The build notably introduced an early version of Windows XP's visual styles system. > Whistler was officially unveiled during a media event on February 5, 2001, under the name Windows XP, where XP stands for "eXPerience". So while the product wasn't released until 2001, the codename and preview builds for developers were already released. [0] https://en.wikipedia.org/wiki/Windows_XP https://en.wikipedia.org/wiki/Windows_XP