Activity Centers

From BetaArchive Wiki

Activity Centers was a Microsoft Windows feature initially intended for Windows Neptune,[1] then Windows ME, then again Neptune,[2] and then Windows XP,[3][4] before being scrapped early in XP's development.

Activity Centers would have been single-window applications, written in a combination of HTML and the Win32 API, that facilitate easy ways to complete common tasks.[4] In Neptune build 5111, Mars.exe serves as the framework (hence, the name "Mars Framework") for running such web pages as framed applications.[5] Mars uses the XML file in the folder of an Activity Center as the page's main layout. The msjava.dll also appears to be the number one dependency of this app, which Ken found when fiddling around with various msjava installations to get the Game Center in that build working.[6]

By default, Activity Centers would have opened to a "home page", which would contain links to the top priority tasks exposed by the application. Secondary Task pages would have provided the user with obvious ways to complete single tasks.[4]

The user interface would have been divided horizontally into a "navbar" and a larger content area. The navbar would have provided a simplified navigational scheme similar to that in a Web browser, so that "back" and "forward" buttons are provided along with other common buttons.[4]


In 1998, a team of 15 Microsoft employees (among them Ben Slivka, Joe Belfiore, and Steve Capps) worked on codename "RedShark", a new user interface for Windows based on the assumption of being project-based. The team proposed that the interface would organize all content according to pages, use the full screen with no window management, have unified search/history, and allow for use by multiple users with roaming features. The interface was intended to debut with Neptune, described as "The Windows Service 1.0" and estimated by Slivka to be released by June 2002.[7][1]

It is not clear if Activity Centers were then moved from Neptune to Windows ME, before being moved again to Neptune.

The Start page, Photo Center, Music Center, Help Center, and System Restore are available but hidden by default in Windows ME build 2358[8][9] However, according to Paul Thurrott, by the release of Beta 1 in the fall of 1999, it was clear that the underlying Activity Center technology was not going to be far enough along to provide the needed HTML hooks into the more traditional Win32 interface. Therefore, only the Help Center (renamed Help and Support Center) and System Restore shipped in Windows ME RTM. AutoUpdate, intended to be an Activity Center, became a traditional application. Windows Media Player was expanded and redesigned to perform the features intended for the Music Center.[4]

Neptune build 5111 came with the Start page, Photo Center, Music Center, Game Center, Help and Support Center, and Microsoft AutoUpdate. The first four could be installed by following these steps. According to Twitter user Albacore (@thebookisclosed), these Neptune Activity Centers could also run on Windows ME build 2380,[10] and made available two files that should be copied into the WIN9X folder of the build's ISO before installation so that the Activity Centers work by default.[11]

Windows Whistler build 2250 contained a Startpage (no spaces) at %SystemRoot%\Web\Startpage.[12] Build 2257 contained the same Activity Centers in Neptune build 5111.[13] Build 2410 contained a redesigned Startpage.[14] According to Twitter user Albacore (@thebookisclosed), the Start button in build 2410 is mapped to the Startpage.[15]


Concept images shared by Paul Thurrott

Thurrott credits John C. Dvorak for the images below. According to Microsoft, these images were not intended to be the final UI, but only a study to see what a task-based Windows interface might look like.[16]

Concept images shared by NTDEV

NTDEV credits Ben Slivka's presentation,[17] but the images below do not appear on it.[1]

Windows ME

Windows Neptune

Windows XP source code

BetaArchive user TinaMeineKatze pointed out that what look like Activity Centers concept art screenshots are available in the Windows XP source code that leaked in 2020.[18]


  1. 1.0 1.1 1.2 Ben Slivka (20 November 2000). Before Slack and Teams: The Windows Service (1998). Retrieved on 17 April 2022.
  2. Thurrott, Paul (5 July 2000). The Road to Gold: The development of Windows Me. Paul Thurrott's SuperSite for Windows. Archived from the original on 16 August 2000. Retrieved on 8 April 2022.
  3. Thurrott, Paul (5 March 2000). Activity Centers, A Windows Me technology showcase. Paul Thurrott's SuperSite for Windows. Archived from the original on 16 August 2000. Retrieved on 8 April 2022.
  4. 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 4.11 Thurrott, Paul (5 July 2000). Activity Centers Preview. Paul Thurrott's SuperSite for Windows. Archived from the original on 4 May 2000. Retrieved on 8 April 2022.
  5. Ken (12 May 2010). Re: Windows Mars in Windows Neptune. BetaArchive. Retrieved on 8 April 2022.
  6. Ken (28 July 2010). Re: Windows Mars in Windows Neptune. BetaArchive. Retrieved on 8 April 2022.
  7. Brad Silverberg 🇺🇦 (@bradsilverberg) (29 March 2021). Ben Slivka @BenSlivka posted his Neptune presentation from August 1998. It’s brilliant but just too far ahead of its time for Microsoft then. Ben has a series of brilliant memos from the mid 90’s.. Twitter. Retrieved on 17 April 2022.
  8. 8.0 8.1 Overdoze (20 March 2019). RELEAK Windows Me build 2358. BetaArchive. Retrieved on 8 April 2022.
  9. 9.0 9.1 9.2 9.3 9.4 Lukas Marsik (21 March 2019). Re: [RELEAK Windows Me build 2358]. BetaArchive. Retrieved on 8 April 2022.
  10. Albacore (@thebookisclosed) (13 April 2021). Build 2380 is the only available build which contains all the internal plumbing for Activity Centers to work. Even Neptune which the centers themselves are taken from doesn't include all the web objects required for them to work. Until now there was no proper way to run these.. Twitter. Retrieved on 16 April 2022.
  11. Albacore (@thebookisclosed) (13 April 2021). If you'd like to try them on your own get a copy of Windows Me Beta 1 (build 2380) and put the files from this repo in the WIN9X folder in the ISO: Once the OS is installed they are ready to use. To get the Start Page simply set this file as your wallpaper. Twitter. Retrieved on 16 April 2022.
  12. Kenneth (30 August 2007). Whistler 2250 Startpage. BetaArchive. Retrieved on 8 April 2022.
  13. Albacore (@thebookisclosed) (4 October 2020). Remember the full screen Start Page that appeared in Microsoft Neptune, the cancelled "prequel" to Whistler/XP? A similar thing turned up in build 2257. Once again web based, but also unfortunately broken due to missing APIs. After that brief stint it disappeared again.. Twitter. Retrieved on 16 April 2022.
  14. Albacore (@thebookisclosed) (4 October 2020). As Microsoft was shifting from web based shell experiences to DirectUI based ones, they also recreated the Whistler full screen Start Page. Build 2410 contains fully functional code for it hidden behind a cryptic registry value. Broken out of box but I was able to get it work!. Twitter. Retrieved on 16 April 2022.
  15. Albacore (@thebookisclosed) (4 October 2020). In case you wonder, the Start button does map to it. The regular Start menu is nowhere to be seen. It's kinda funny that we could've faced the Windows 8 predicament 10 years early.. Twitter. Retrieved on 16 April 2022.
  16. 16.0 16.1 16.2 Thurrott, Paul. Windows XP: The Road to Gold. Paul Thurrott's SuperSite for Windows. Archived from the original on 28 August 2001. Retrieved on 8 April 2022.
  17. NTDEV (@NTDEV_) (28 August 2023). Looks like Microsoft's desire to make the Start menu a full-screen experience started way before Windows 8. Here are some mockups from 1998 showing a proposed Start screen and full-screen apps for Windows Codename Neptune. Basically, it's Metro but with 90's ✨aesthetic✨.. X. Retrieved on 22 October 2023.
  18. 18.0 18.1 18.2 TinaMeineKatze (26 September 2020). Re: M$ source code leak apparently contains XP. BetaArchive. Retrieved on 8 April 2022.

See also

BetaArchive forum

External links