Windows 2000 Family Professional

Windows 2000 Family Professional is an operating system for emulators and etc mainly, loading older versions of Windows.

Operating systems are included

 * Windows 1.0
 * Windows 2.0
 * Windows 3.0
 * Windows 95
 * Windows 98
 * Windows 2000

Dev_777_Build 186
This build is the earliest known build confirmed and to be found on the MSDN Developer Forums around January 1999 being mentioned over 30 times. Bill Gates even mentioned this build in the 2000 Build Event hosted 3 months later. However, most thought this build was compiled around December of 1998 but, just 10 minutes after the 2000 Build Event hosted by Bill Gates. The build's screenshots were leaked however showing only the desktop and nothing else. But, the desktop's screenshot looks like it's one of those first ever developer builds of Windows 2000 from 1997-1998. However, this build has not been leaked, ever since the introduction of Windows 2001 Family Professional in 2002.

Dev_1267_Build 1270
This is build was leaked and complied on January 22, 2004 by Jon Will on the archives network for builds. This build is also is the earliest build to ever get leaked. According to this very early release note the build was to be compiled around late 1999 and, no earlier than 2000 since, the notes later on have changed for March 2000's public beta release. For it's release notes there's a document called "developmentnotes.txt" if opened it will appear:

RELEASE LICENSE NOTICES: Copyright 1999, Microsoft All rights reserved

THIS SOFTWARE IS PROVIDED BY MICROSOFT AS IS AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MICROSOFT BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.