Windows 95 build 34

Windows 95 build 34 (codenamed Microsoft Chicago) is one of the earliest confirmed pre-release builds of Windows 95. It is mentioned in file  from later Chicago builds (e.g. 58s).

'''PLEASE NOTE: Some information below is based on observations from the video and leftover files, as well as speculation by the author of this article. Therefore it should be treated as such, rather than fact.'''

system.ini, Boot, "shell="   ,"shell=mergereg.exe" system.ini, 386Enh, "device=?Pcommdrvr.386" system.ini, 386Enh, "device=?Pw3_prtcl.386" system.ini, 386Enh, "device=?Pxon_xoff.386" system.ini, 386Enh, "device=?Pcts_rts.386" system.ini, 386Enh, "network=vbrowse.386" system.ini, 386Enh,"cachepages=" system.ini, 386Enh,"device=regvxd.386" system.ini, Boot,,"scrnsave.exe=stressme.scr"
 * Nagaras MergeReg.exe as the shell
 * Remove these as of build 34. Were reverting back to Win 3.1 Comm support.
 * Remove these as of build 34. Were reverting back to Win 3.1 Comm support.

The file also contains the following line:


 * !:README.EF     removed for M32 external release. MC.

is a remnant of previous Chicago builds, together with,  ,   and. It gives a pretty good insight into the installation process of pre-58s builds. These files indicate that early Chicago setup was merely a rebranded Windows 3.1x setup and did not include major changes or new features. The new setup, as seen in build 58s, was likely introduced as part of the M4 stage.

Early leaked builds also still include the old Windows 3.1x-like bootscreen,, which is also a leftover from previous builds and may have been used in build 34.

Internal documents
An internal Microsoft document claims there was an early PDK from M3 stage sent to 40 ISVs in 1993-03. The build is said to have had "Win32s level support for 32-bits" and "lacked the new shell" (Chicago Shell/Explorer). According to another document, "M3 prebeta MS release" was made on 1993-01-22. The first PDK release, mentioned above, is now referred to as "M32" (possibly meaning M3.2, a naming convention seen later on in the development of Windows 95) and was released on 1993-03-08, according to the document.

Judging by the information gathered from  and the documents, it appears build 34 could be the M32 external release from early 1993-03 that was sent to a few people, which means it was probably compiled in late 1993-02 or early 1993-03. The M3 prebeta MS release was most likely released internally at Microsoft (as the name suggests) and may even be related to the builds shown in the Usability Testing video.

YouTube video
There is also a video claiming to show this build by user George Wolfowitz. As this build remains unleaked, the authenticity of the video can't be confirmed. Some observations from the video:


 * "Personal" and "Programs" folders on the desktop are only links to these folders
 * The help start menu icon is from build 58s, but the computer icon is the same as in usability testing builds
 * The Help menu is missing some items
 * The bootscreen shown is the already mentioned, also found in later builds (though no longer used)
 * "About Chicago" dialog properly displays user and company information, unlike build 58s which displays placeholder strings
 * Controls.sys titlebar icon is different
 * 3 control panel item are missing while some others have different icons

Fake screenshots
Several screenshots of this build were posted by betaguy224, but they were proven to be fake by the Usability Testing Builds video.