Development of Windows XP

Development of Windows XP started in 1999 after Windows Neptune and Windows Odyssey were cancelled. The result, "Whistler", became Windows XP. Windows XP was finished on August 24, 2001, and the operating system was released on October 25th. 
Beta versions and Release.
In June 2000, Microsoft began the beta testing for Whistler. On July 13, 2000, Microsoft said that Whistler would be released in late 2001. Microsoft also released the first preview for the operating system, 2250. Build 2257 introduced an early version of Windows Firewall and a Start menu with two columns.
Microsoft released Whistler Beta 1, build 2296, on October 31, 2000. In January 2001, Internet Explorer 6 was added in build 2410. Builds 2416 and 2419 added new wallpapers.
On February 5, 2001, the name of Windows XP was announced. The name XP was used because XP is short for experience. In April 2001, Microsoft stated that XP would not support Bluetooth or USB 2.0. USB 2.0 support was later added with Service Pack 1. The last builds focused on fixing bugs, user feedback, and final changes before XP was released.
In June 2001, Microsoft indicated that it would spend at least US$1 billion on marketing Windows XP. 
On August 24, 2001, Windows XP build 2600 was released to PC builders, and on October 25th, it became open to the public.