Development of Windows XP

Development of Windows XP started in 1999 in the form of Windows Neptune. Windows XP was developed for 18 months, from December 1999 to August 2001, and was released on October 25, 2001.

Neptune and Odyssey
Neptune (build date of December 27, 1999 with a build number of 5111) was shown to selected groups of internal users and TechNet subscribers in 1999 (though it is still debated as to whether it was an alpha release or a Technology Preview). It was developed from the Windows 2000 codebase. "Neptune" was intended to be the next consumer version of Windows after Millennium. Only build 5111 was distributed outside of Microsoft.

In early 2000, it was reported that the development teams working on Neptune and Odyssey, an update to Windows 2000 for business users, had been amalgamated to work on a new project codenamed Whistler, which was eventually released as Windows XP.

Early beta program
Build 2202 (released on February 2, 2000) The entire OS differed little from Windows 2000, and much of the operating system (boot screen, setup routine, etc.) still read as Windows 2000. However, the "for testing purposes only" can still be seen in the corner of the desktop, and the log-on screen reads "Windows Whistler".

Build 2223.1 (with a build tag of main.000411-2307) was released on April 11, 2000, and was previewed at the WinHEC (Windows Hardware Engineering Conference) in late April 2000.

On June 30, 2000, Microsoft announced the start of the "Whistler" technical beta program.

Starting from build 2202, Microsoft introduced the new UI technology to various builds of "Whistler". Visual Styles, as it was called during this phase, was based on a skinning engine similar to Stardock's WindowBlinds. During this period, Microsoft introduced the "Professional" (later renamed to "Watercolor") theme which was dropped in January 2001. Also during this period, Microsoft began development on a new look for the Start menu.

Build 2250 (with a build tag of main.000628-2110) was the first build of "Whistler" released to testers, on July 13, 2000 at the Professional Developers Conference (PDC) in Florida. It closely resembled Windows 2000 and Windows Me and didn't offer many new features, but it was the first build to feature Visual Styles. It also featured a task-based Control Panel. The new Start menu Microsoft had been working on was hidden in build 2250.

Build 2257 (with a build tag of idx01.000810-2103) was released in August 2000, after a month of inactivity. This build included the new Start menu in the UI, and it was the first to feature the results of Microsoft's "clean desktop" initiative. Also, the Professional Visual Style was tweaked with new colors. This was also the first build to include Microsoft's personal firewall.

Build 2267 (with a build tag of idx01.000910-1316) was released on October 3, 2000. It offered small improvements, but no major new features. But it allowed the user to modify the "look and feel" of the system with a functional Display Properties dialog. Build 2267 also introduced a "Compatibility Center", which would eventually allow users to research whether particular hardware devices are compatible with this OS.

Build 2287 (with a build tag of beta1.001012-1640) was the final pre-Beta 1 release build. It featured a redesigned setup routine, a redesigned Help & Support Center (the previous versions were lifted from Windows Me), and some UI tweaks. It was also the first build to use Dynamic Updates, a new Setup feature.

Beta 1
Build 2296 (Beta 1, with a build tag of 2296.beta1.001024-1157) was released on October 31, 2000. This first pre-beta of Windows XP.In this build, the Start Panel has been replaced by a new simple Start Menu, an MMC-based taskpad that is intended to make it easier to find frequently-accessed applications. This was the first build to group similar taskbar buttons and hide inactive icons in the system tray. Backward compatibility has been also added to this build. User switching was enabled in this build. In this stage of development, on November 13, 2000, Microsoft misannounced that "Whistler" will be called Windows 2001. This name was later dropped.

Build 2410 (with a build tag of main.001208-1937 and idx02.001212-1507) was released to testers on January 4, 2001. It included a number of new features, such as some new high-color icons, a renaming of the Professional theme to "Watercolor", minor changes to the simplified Start Menu, a new sample UI skin, some tweaks and fixes and the inclusion of Internet Explorer 6 with the new Media and IM Explorer bars, Outlook Express 6, Windows Movie Maker 1.1 (not included with server editions), MSN Explorer 1.1 (not included with server editions), Windows Media Player 8.0, and Internet Information Services 5.1.

Build 2416 (with a build tag of idx01.010104-1958) was released to testers on January 16, 2001. It featured a more attractive Help and Support Center, MP3 support in Windows Media Player 8, a new File and Transfer Settings Wizard, a cascading Start Menu, new performance options, and System Restore integration with System Properties.

Build 2419 (with a build tag of idx02.010113-1154) was released to testers on January 23, 2001. It debuted the final Windows XP Setup routine, and much of the final Windows XP wallpaper selection. It was the first build to contain Windows Product Activation, which was added to help cut down on piracy. It was also the last build to contain the "Watercolor" theme.

Beta 2
By the end of January 2001, the final naming of "Whistler" became an issue that news and rumor sites alike began posting their guesses. Eventually, the "XP" moniker was used, for "eXPerience." Microsoft announced the final name of "Whistler" on February 9, 2001. Since then, "Whistler" was known as Windows XP. Also, on 9 February 2001 that day, technical reviewers received a private demonstration of "Whistler" build 2428 at Microsoft. Build 2428 has a Date Stamp of 9 February 2001 and was known as Whistler Beta 2.

Build 2462 (Windows XP Beta 2, with a build tag of main.010315-1739) was released on March 23, 2001.

Pre-RC1 and RC1
Responding to criticism that it wouldn't be supporting the upcoming USB 2.0 standard out of the box with Windows XP, Microsoft issued a letter to its customers on April 23, 2000 explaining the decision. "Microsoft is a big supporter of both USB 2.0 and Bluetooth, as well as many other connection and wireless standards, such as IEEE 802.11b, IEEE 1394, and USB 1.0", wrote Carl Stork, General Manager of Windows Hardware Strategy. "We have been and remain committed to delivering support for these new standards in Windows XP and some of our other operating system products. The issue for USB 2.0 and Bluetooth is only the timing of availability for native support for Windows, and not any decision to choose support for one technology over another. Because of the lack of production-quality devices to test, and because Windows XP must be ready for PCs that will ship for the 2001 holiday season, Windows XP will not have native support for either technology when it is first released to PC system manufacturers. Microsoft’s goal is to deliver support for both Bluetooth and USB 2.0 soon after Windows XP is first available." By late July, the company was already shipping beta drivers for USB 2.0.

Build 2469 (with a build tag of idx02.010508-1228) was released to testers on May 12, 2001. Major changes to Networking and Net card drivers were implemented in this build. This build also included minor updates to the Home Network Wizard, the RAS client connection wizard; the Base, Kernel, Plug and Play and Power Management; performance, reliability, boot time, application launch, setup, uninstall, and Windows 98/ME upgrades; security & directory services, mainly new restrictions on local account login using blank passwords; and help, management, and remote desktop/assistance.

Build 2474 (with a build tag of main.010508-1907) was released internally on May 17, 2001. It wasn't given to testers, but it was the first build to feature the new Product Activation UI, which now used new XP-style dialogs. It was also the first build to include a beta of Windows Messenger 4.

Build 2475 (with a build tag of idx01.010514-2023) was released to testers on May 24, 2001. This build featured a new boot up logo with a black screen that now reads Windows XP, a new introductory movie, a Welcome to Windows screen featuring a borderless window, a waving flag animation on the Welcome screen that was later dropped, an icon for Remote Assistance in the root of the All Programs menu, and various tours of Windows XP and MPXP in Help and Support. Also, Setup was branded with "RC1" text.

Build 2481 (with a build tag of main.010523-1905) was released internally on June 1, 2001 and given to testers on June 6. This build featured a number of improvements, including a new Windows XP tour and two color schemes based on the Luna UI. Then called "Homestead" and "Metallic", for their green and gray colors, respectively, the color schemes were among many others that Microsoft was working on, but only these two were included in the final release.

After Build 2481 was released, there would be no more changes to the Windows XP's GUI, meaning that the UI is very close to what it will be in the final product. Hardware compatibility was also finalized, meaning that Microsoft didn't add device support beyond what was then planned.

Build 2486 (with a build tag of main.010602-1927) was released to testers on June 15, 2001. For the first time, this build of Windows XP Home Edition could support multiple monitors, including dual-view. Previously, Microsoft had said that Home Edition would support only one display. 2486 was also the first build to include the four "sample pictures" that shipped in the RTM version of XP.

Build 2494 (with a build tag of main.010613-1739) was released to testers on June 21, 2001, which was the first to offer up balloon help suggesting that users tie their Windows logon to Passport. It was also the first build to feature the new Windows Messenger UI.

Build 2505 (RC1, with a build tag of main.010626-1514) On July 2, 2001, as Release Candidate 1. There were no changes from previous builds. This was the first build released to the public via the Windows XP Preview Program (WPP) since Beta 2.

"The feedback that Microsoft has received from more than half a million beta testers tells us loud and clear that people are super-excited about the experiences Windows XP enables and that we're in the home stretch for delivering the system to our customers", said Jim Allchin, group vice president of Microsoft's Windows division, referring to the many feedbacks Microsoft had been receiving. "Today's release of RC1 further underscores Microsoft's commitment to excellence and to delivering the highest-quality product to our customers on October 25."

Pre-RC2 and RC2
Amazon's Mistake

On July 7, 2001, Amazon.com mistakenly posted Windows XP for sale on its site, and included pictures of its box. Microsoft asked the company to take down the pages, which they did, although Amazon would later make the same mistake a day before XP was released to manufacturing. Amazon would later make another mistake when they revealed Windows Vista pricing before release.

Microsoft revealed that another interim release of Windows, code-named Longhorn, eventually released as Windows Vista, would follow Windows XP, moving the release date of Windows 7 (at the time codenamed Blackcomb) back at least two more years.

Build 2520 (with a build tag of main.010717-1624) was also released on the same day. There were no changes from previous builds although it was the first build to include the ability to remove Internet Explorer from Windows XP.

Build 2526 (with a build tag of xpclient.010724-1758) was eventually released as Release Candidate 2 (RC2) on July 27, 2001. RC2 didn't include any new features, although it had the ability to remove Internet Explorer, and this was the first time most users had seen it. Beyond that, Microsoft said that RC2 was primarily about bug fixes and fit-and-finish work.

Pre-RTM and RTM
Build 2535 (with a build tag of 2535.xpclient.010803-1621) was released on August 8, 2001, though it offered no visual changes.

Build 2542 (with a build tag of 2542.xpclient.010811-1534) was released on August 14, 2001. It was the first build to require testers to use new types of product keys. Like the previous build, this build offered no visual changes at all. Microsoft said that this build was primarily provided to regress existing 'fixed' bugs, to uncover any last minute ship-stopper regressions, and to get a final sanity check prior to RTM.

Build 2545 was forked to Build 2600 on August 20, 2001, and the company began hammering away at this final build for RTM, alerting the press about its progress and explaining the remainder of the schedule.

Build 2600 (with a build tag of 2600.xpclient.010817-1148) On August 24, 2001, was declared as RTM, and was handed off to PC manufacturers at a media event held on the Microsoft campus.

Windows XP was released on October 25, 2001 to the general public and to retailers worldwide.