Windows

Windows
Developer	Microsoft
Publisher	Microsoft
Platforms	x86 16-bit, IA-32, x86-64, ARM, Itanium, DEC Alpha, MIPS, PowerPC
Released	1985-present
Added to Museum	Windows 10: July 15, 2015 NT Workstation 4.0: May 15, 2020

Windows is the name of a series of operating systems created by Microsoft.

History

Windows 1.0, 1.01, 1.02, 1.03, 1.04, 2.0, 2.1, and 2.11 had 16-bit file access. Windows 3.0, 3.1, 3.11, Windows for Workgroups 3.1, and the Simplified Chinese-exclusive Windows 3.2 also had 16-bit file access but were not compatible with Windows 1.0, 2.0, and the updates of these versions due to the use of protected mode.

All of the above versions relied on the DOS operating system for essential functions, and thus in most cases were restricted to the 16-bit architecture of DOS. Windows for Workgroups 3.11 also relied on DOS but had a 32-bit protected mode driver instead of the standard 16-bit driver to allow for 32-bit disk access.

Windows NT 3.1 was the first version that was a complete 32-bit operating system. It ran DOS programs through a DOS-based Virtual DOS Machine. This VDM was also present in Windows/386 2.10, 3.0, 3.1, and Windows for Workgroups 3.1 and 3.11. 16-bit Windows applications were run through a compatibility layer known as Windows on Windows.

The DOS-based VDM and WoW compatibility layers for backward compatibility continued in Windows NT 3.5, NT 3.51, NT 4.0, 95, 98, 98SE, 2000, and ME. Windows Vista, 7, 8, 8.1, 10, and 11 dropped the DOS-based VDM but the 16-bit Windows on Windows compatibility layer still exists on 32-bit versions of Windows. 64-bit versions, however, do not have a 16-bit compatibility layer.

Versions of Windows

Title	Released	Notes
Windows 1.0 Windows 1.01 Windows 1.02 Windows 1.03 Windows 1.04	1985 1985 1986 1986 1987	1.0 was the "Premiere Edition". It wasn't for sale. It was a demo for reviewers and retail outlets. 1.01 was the original retail release. 1.02 was an international release. 1.03 synced the drivers in the American version with the international version. 1.04 had support for PS/2 computers with a PS/2 mouse driver in the "IBM PS2 Collegiate Kit".
Windows 2.0 Windows 2.01 Windows 2.03 Windows 2.1	1987 1987 1987 1988	2.0 added overlapping windows, more keyboard shortcuts, and the control panel. 2.1 was split into 286 and 386 versions and required a hard drive. Windows/286 had a himem.sys file for access to the high memory, freeing conventional memory. Windows/386 accessed virtual 8086 mode of the i386 allowing for multi-tasking of DOS apps.
Windows 3.0 Windows 3.0a Windows 3.1 Windows for Workgroups 3.1 Windows NT 3.1 Windows for Workgroups 3.11 Windows 3.11 Windows 3.2 Windows NT 3.5 Windows NT 3.51	1990 1990 1992 1992 1993 1993 1993 1993 1994 1995
Windows 95 Windows NT 4.0 Windows 98 Windows 98SE Windows ME	1995 1996 1998 1999 1999	Windows NT 4.0 introduced the Windows 9x interface to the NT line.
Windows 2000	1999	The 5.0 version of the NT kernel in Windows 2000 tied the Windows and NT line into one product.
Windows XP Windows Server 2003 Windows Server 2003 R2 Windows Home Server	2001 2003 2005 2007	The 32-bit version had the 5.1 version of the NT kernel. The 64-bit and server versions had the 5.2 version of the NT kernel.
Windows Vista Windows Server 2008	2007 2008	Had the 6.0 version of the NT kernel.
Windows 7 Windows Server 2008 R2 Windows Home Server 2011	2009 2009 2011	Had the 6.1 version of the NT kernel.
Windows 8 Windows Server 2012 Windows 8.1 Windows Server 2012 R2	2012 2012 2013 2013	Windows 8 and Windows Server 2012 had the 6.2 version of the NT kernel. Windows 8.1 and Windows Server 2012 R2 had the 6.3 version of the NT kernel.
Windows 10 Windows Server 2016 Windows Server 2019 Windows Server 2022	2015 2016 2018 2021	Had version 10.0 of the NT kernel.
Windows 11 Windows Server 2025	2021 2024	Still had version 10.0 of the NT kernel.