Windows NT 3.1 build 404

Windows NT 3.1 build 404 is the March 1993 beta of Windows NT 3.1. This build was only available in the Workstation edition for many years, until an Advanced Server version of this build was later found and leaked on 26 March 2021.

Changes

 * Changed the setup to resemble the RTM version.
 * Added some new applications like Mail and Schedule+ which are inherited from Windows for Workgroups 3.1.
 * Introduced Registry Editor, which is included in every Windows NT build ever since this one.
 * Changed the default color scheme to match the one used in Windows 3.1 instead of the version used in Windows 3.0.

File differences
The following files have been introduced or removed compared to build 340: