Windows NT 3.1 build 438

Windows NT 3.1 build 438.1 is the April 1993 beta of Windows NT 3.1. It's not that different from build 404.1, which was released a month earlier. A version of the build in the Alpha AXP architecture was shared on 4 August 2020.

Prior to its upload, it was mentioned in an internal Microsoft e-mail from August 1993 where it states that the build was delivered to Novell in order to test their NetWare Client for the then-upcoming NT operating system; the e-mail also states that Novell had received the June 1993 beta three weeks later than what was originally promised by Microsoft.

New features and changes

 * The Control Panel and Windows NT Setup icons are now updated to match the ones in Windows 3.1.
 * has been updated to version 3.1 as seen in the RTM and it no longer shows a list of loaded drivers unless the user adds the  switch to.
 * When changing the display type in Setup, a warning message will appear, as selecting a display type incompatible with the current installed one will make Windows NT unusable, necessitating reinstallation. Setup recommends to select the proper display type after Windows NT has been fully installed, as the user still has access to the Last Known Good Configuration to recover the previous hardware state.
 * There are more options when selecting the display type, such as support for ATi display adapters, "VESA VGA (800x600, 16 colors)", as well as "S3 (1280x1024, 256 colors)".
 * has been simplified. This change has been reverted in Windows NT 3.5 build 612.1.

File differences
The following files have been introduced or removed compared to build 404: