Windows NT 3.1 build 475

Windows NT 3.10.475.1 is mentioned in an internal Microsoft e-mail from 1993-08. Apparently, this build was delivered to Novell in 1993-06 to test their NetWare Client for NT. The e-mail also claims Novell had also received the April 1993 beta sometime earlier.

It was found on 2017-02-25 and uploaded to BetaArchive. This build refers to itself in the boot screen and Winver as build 4755, and as build 475 on the default Windows NT wallpaper. It's possible that 4755 was intended to be 475.5. A similar thing can be observed in the final build (3.10.511.1), where the kernel's file version is 3.10.5098.1.