Windows 3.1 build 034f

Windows 3.1 build 034f is the official Beta Release 1 of Windows 3.1. This build was originally provided by an OSBetaArchive member, whose 5.25" copy had the second floppy disk unreadable, leading other community members to rebuild it using files from other builds. This also meant that the build has been mislabeled as build 034e for a long time, as the  file holding the actual build number was included on the broken disk. In late 2020, community member ReflectiaX obtained a 3.5" copy of this build. He then dumped his disks in January 2021, clearing out any doubts about the build. This build was also reviewed in the December 1991 issue of Yugoslavian computer magazine Računari ("Computers").

Setup has a new interface, letting the user choose either "Quick install" (Default) or "Full install" (Custom). The Windows error debugger (Dr. Watson) is included and starts automatically with Windows. Object Packager has a unique icon and name in this build. There is a bug with the Setup Applications part of the setup where it will detect non-existent programs and attempt to find them.

This build is currently the earliest available build of Windows 3.1 to have built-in Video 7 drivers supporting resolutions higher than 640x480 in 8-bit color mode.

This build is also the last build of Windows to run in Real Mode, and subsequent builds dropped support for the Intel 8086/8088 and its variants.