Windows 3.0 undated 1989 build

An undated screenshot of what is presumed to be a pre-release build of Windows 3.0 was shown by Craig Brockschmidt, the developer of the Windows 3.0 Calculator application, running Calculator version 3.00.13 on his website. . This is earliest known build of Windows, which use Programm Manager.

Given that the calculator in Windows 3.0 build 55 has the version number 3.00.16, this particular build could be earlier than 3.00.55. It is also possible that this build would be the same as build 48.