Windows 3.0 build 33

Windows 3.0 build 33 is a build of Windows 3.0 that was uploaded on 23 September 2022, along with some disks of its software development kit. The build was also mentioned in an internal Microsoft e-mail from August 1989, where it is noted that the build is slow due to extensive debugging hooks.

This is the last available build to use MS-DOS Executive as the default shell, as the next available build, build 55 already uses the newer Program Manager. However, references to the new shell can already found in the available copy, and it is likely that it was merely omitted for this release. It is also the last known build of Windows 3.0 to feature a debug watermark before returning in debug compiles of Windows 3.1.

Installation
This build does not ship with a setup application, so the contents of the floppy disks should be manually copied to.

Using MS-DOS 3.31 is recommended.

To get 386p mode working, add  to. It is also recommended to add  to.

The display driver is set to VGA by default. In order to use the proper display driver, edit the display.drv line in  from   to:
 * for Video 7 VGA
 * for 8514/A
 * for CGA
 * for EGA
 * for Hercules
 * for Compaq

Operating modes
Unlike build 14, which only supported 386 and better systems with an early Enhanced Mode, this build can run in all three modes known from the final version, although slightly different names are used for them: The r term is used for the x86 real mode, while the letter p stands for protected mode.
 * Real Mode is known as 286r mode,
 * Standard Mode is known as 286p mode,
 * 386 Enhanced Mode is known as 386p mode.

The kernel executables for the two protected modes also use file names that are different from later builds, as the Standard Mode kernel is  and the 386 Enhanced Mode Kernel is. By build 55, they would be renamed to  and , respectively. The real mode kernel executable is, same as in the final version.

By default, the system starts in 286r mode when invoking  with no parameters, unlike later builds that perform basic detection to determine the optimal mode. To launch the system in another mode,  must be invoked with a parameter. The  and   parameters, which are accepted by the final version, start Windows in 286p or 386p modes, respectively. Additionally, the  parameter was also found to launch Windows in 386p mode.

Remnants referring to applications not included
While there is no setup application for this build, a leftover  information file can be found within the disks' contents.

The contents of  indicate that the Setup identifies as "Microsoft Windows/386 Version 3.00", and also supports installing a Windows runtime a la earlier versions of Windows.

The list of files installed by Setup include  and , as well as several utilities that were apparently removed from the pre-release SDK distribution (such as an early version of Solitaire and an unknown version of Terminal and Calculator).

As this build contains the new Control Panel (replacing the older one from Windows 1.x/2.x) and the Print Manager, a possible reason for these applications not being included is to hide as much of the new UI as possible from developers outside of Microsoft at this point (as this build was provided to developers under a very strict NDA according to contemporary accounts to test their applications under 286/386 protected mode Windows). Microsoft did something similar a few years later; in early 1993 a Milestone 3 build of Windows 95 was sent out to 40 software developers with Cabinet removed. .

It is also possible the applications were too unstable and buggy to send out to developers.

Bugs
This build is quite early and rough and exhibits numerous bugs:


 * The placement of the text on every single Button control is misaligned and is above where it should be.
 * Under rare circumstances, the kernel may attempt to launch the nonexistent Program Manager instead of the MS-DOS Executive during startup.
 * Trying to use a DOS window in display modes other than VGA seems to crash the OS.
 * Some icons in Control Panel look a bit broken under the 8514/A display mode.
 * Character kerning is partially broken. This is visible when typing into a text box, as characters move around slightly with each typed character.

Programs

 * Windows Help crashes the entire OS in 286r mode, and attempts to run as a DOS application (despite being a Windows application, version 3.00.0202) in 286p and 386p mode. An initial look indicates that the file may be corrupted around the 0x200 to 0x1000 range.
 * The Task Manager is not present and attempts to launch it will fail.
 * Calendar may crash the entire OS when in 386 mode.