Windows 95 build 58s

Microsoft Chicago build 58s is a Milestone 4 build of Windows 95. It is the first release of the Chicago Preliminary Development Kit (PDK) and the earliest available build of Windows 95, although earlier builds are known to exist.

New features

 * This build runs on top of a new version of MS-DOS, 7.0, which now starts Windows automatically.
 * It also features a new type of bootscreen, which is stored inside  in the root of the system partition.
 * Program Manager and File Manager from Windows 3.x have been replaced by a new, unified shell called Cabinet, a very early form of Windows Explorer which is still 16-bit in this build.
 * The new shell makes better use of the desktop than Windows 3.x, allowing the user to place icons representing programs, files and folders on it.
 * At the bottom of the screen is the taskbar, which in this build serves as a folder for storing shortcuts, files and folders, not for displaying running programs like in later builds.
 * Minimized programs instead appear similar to Windows 3.x, floating around the desktop as tiles with the program's name beside the icon.
 * A new setup program to install Windows is used, but  requires to be opened in Windows. You can start setup from DOS by running , which launches a basic Windows environment based on Windows 3.1. The older setup program previously used to install Windows 3.1 is still there.
 * The taskbar features three buttons and menus for accessing common commands: System, Search and Help menus, which were later merged into a single Start button.
 * When shutting down, it shows a reminder that you can turn off the computer if there is no disk activity. However, after a few seconds, it exits to MS-DOS, as the safe to shutdown screen seen in later builds has not been implemented yet.
 * When installed beside an existing installation of Windows 3.1x, Chicago can be configured to run that installation of Windows 3.1 in a window, similar to a virtual machine.

Bugs and quirks

 * As with other Windows 9x builds, the hard disk needs to be partitioned and formatted before installing this build.
 * The new setup doesn't ask for username and organization information, leaving the placeholder values of "Unknown User" and "Unknown Organization" in place.
 * The floppy disk driver in this build is very buggy and won't work most of the time. Cabinet will either display nothing or garbage when the floppy drive is accessed. To access the content of a floppy drive, return to MS-DOS and copy the content to the hard drive.
 * Even if no network is installed during setup, an error saying "Cannot find NETWORK.DRV" will be displayed on startup, but it's harmless and can be removed. See below for a fix.
 * If you install directly from a CD, an error saying "Cannot access D:\" will be displayed on every boot, but can be skipped. See below for a fix.
 * Cabinet will not remember your view settings and many of the menu options don't work as they're not implemented yet.
 * The build may hang or crash randomly and can be rather slow at times.
 * Some copies of this build are missing the file, which must be skipped for setup to continue.
 * In Network's Help menu, writes "About File Cabinet".

Getting rid of startup items
Three programs are configured to run on startup by default: Dr. Watson, Chicago Beta Warning and Tracker. The former two can be disabled by removing their links (shortcuts) from the Startup folder, which is inside the Programs folder on the desktop.

Tracker can be disabled by removing it from the  value in the   section of.

Configuring a CD drive
The best way to get the CD drive working is to use an Adaptec AHA-154x SCSI adapter and a SCSI CD-ROM drive, drivers will be automatically installed and they'll work. While ATAPI CD-ROM drive support is incomplete, this build can still access the ATAPI CD-ROM drive without hanging if installed prior to setup, unlike some of the later builds.

Fixing "Cannot access D:\" error
Open  and change the line   to , then save the file.

Fixing "Cannot find NETWORK.DRV" error
Create a dummy (empty)  file inside the   folder or configure a network.

Old setup
There are many old setup files on the unmodified disc which may have been used in builds prior to 58s. Running  in the   directory of the setup disc will launch the Windows 3.1x style setup, but the installation process will fail at the text stage due to 184 missing files.

It looks almost exactly like the Windows 3.1x setup, except for branding changes from "Windows" to "Chicago". It was possibly designed for a debug build of Chicago since it asks for many  files, a few debugger executables and batch files. Most of those  files are present in early Win32s builds meaning 32-bit support in Chicago was still at Win32s level in early June 1993. It also asks for many components from Windows for Workgroups 3.1x that are missing from the setup disc.

After copying files in the GUI portion of Setup, Setup will attempt to run  which is not present in this build. Setup will then launch Network Setup and it will most likely fail due to missing files.

Despite this, it is possible to install this build using the old setup, but the result produced is only a semi-working version of this build with visual glitches. The boot screen is  used by earlier builds instead of the new animated   boot screen. About dialog reports "Windows for Workgroups Version 4.00.58s" as the old setup copies the old  during installation. File Cabinet will fail to launch due to missing registry entries, but Program Manager works fine. All program groups are present due to the Group File Converter not being executed automatically upon boot. The old setup does not install MS-DOS, therefore it is required to have MS-DOS 7.0 installed before installing Windows.