History of Windows: Every Major Version From 1.0 to Windows 11
Windows has been through more than forty years and two very different code bases: the DOS-based line (Windows 1.0 to Me) and the Windows NT line (NT 3.1 to Windows 11). This article gives a dated tour of the major releases, what changed in each, and why the NT line won. It is a reference you can check version numbers against: the table near the end lists the internal version numbers you see with winver or ver.
The DOS-based era (1985 to 2000)
- Windows 1.0 (1985): a graphical shell on top of MS-DOS with tiled windows; see the DOS article.
- Windows 2.0 (1987): overlapping windows and better keyboard shortcuts.
- Windows 3.0 (1990) and 3.1 (1992): the first big success, with Program Manager, File Manager, virtual memory and TrueType fonts. Windows for Workgroups (3.1 in 1992, then 3.11) built in peer-to-peer networking.
- Windows 95 (1995): the Start menu, taskbar, long file names and Plug and Play; a 32-bit consumer OS that still ran on DOS.
- Windows 98 (1998), 98 SE and Me (2000): USB support, FAT32, Internet Explorer integration. Me was widely regarded as unstable and was the last DOS-based release.
The Windows NT line (1993 to today)
In parallel, Microsoft built a new, portable 32-bit operating system designed by a team led by Dave Cutler. It had a real kernel with protection, the NTFS file system, security and multi-user features. It began with Windows NT 3.1 in 1993 and grew from there:
- NT 3.5 and 3.51 (1994 and 1995), NT 4.0 (1996): NT 4.0 adopted the Windows 95 interface and became a common server and workstation OS.
- Windows 2000 (2000): Active Directory, better hardware support and reliability.
- Windows XP (2001): merged the consumer and business lines onto NT. It lived for over a decade, and its end of support in April 2014 was a major event for organisations.
- Windows Server 2003 (2003): a mature server platform.
- Windows Vista (2007): User Account Control, a redesigned graphics stack (Aero) and better security, with a difficult launch because of driver and performance problems.
- Windows 7 (2009): refined Vista, and became the benchmark that Windows 8 and 10 were measured against.
- Windows 8 and 8.1 (2012 and 2013): a touch-oriented interface with the Start screen, which many desktop users disliked.
- Windows 10 (2015): returned the Start menu and introduced “Windows as a service”, meaning feature updates delivered regularly rather than a new version every few years. Windows 10’s general support ended on 14 October 2025 (Extended Security Updates and long-term servicing editions follow separate schedules).
- Windows 11 (2021): a redesigned interface with a centred Start menu, stricter hardware requirements (TPM 2.0, Secure Boot capable UEFI, supported 64-bit CPUs), and Android app support in its early years (since discontinued).
Version numbers at a glance
| Product | Release | Internal version |
|---|---|---|
| Windows 95 / 98 / Me | 1995 / 1998 / 2000 | 4.0 / 4.10 / 4.90 |
| Windows NT 4.0 | 1996 | 4.0 |
| Windows 2000 | 2000 | 5.0 |
| Windows XP | 2001 | 5.1 |
| Windows Vista | 2007 | 6.0 |
| Windows 7 | 2009 | 6.1 |
| Windows 8 / 8.1 | 2012 / 2013 | 6.2 / 6.3 |
| Windows 10 | 2015 | 10.0 (build 10240 onward) |
| Windows 11 | 2021 | 10.0 (build 22000 onward) |
Windows 11 still reports version 10.0, which is why scripts must check the build number (22000 or higher) to tell Windows 10 and 11 apart. Run winver, or in PowerShell [System.Environment]::OSVersion.Version, and (Get-CimInstance Win32_OperatingSystem).Caption to see your own.
Why the NT line won
- Protected memory and processes: a crashing program could not bring the OS down.
- A real security model: users, permissions, auditing and a secure logon, later joined by domains and Active Directory.
- Portability: a hardware abstraction layer (see what is a HAL) let the same system run on different CPU types.
- A better file system: NTFS with journaling and ACLs.
Lessons for admins
- Support dates matter. Check the Microsoft lifecycle page before deploying, and plan upgrades before end of support, because unsupported systems no longer get security fixes.
- Compatibility is a design goal. 32-bit programs still run on 64-bit Windows through WOW64, but 16-bit programs do not.
- Keep an inventory. Legacy systems often hide in labs, factories and back offices.
Common questions
What was the last version of Windows based on DOS?
Windows Me, released in 2000.
Why was there no Windows 9?
Microsoft moved from Windows 8.1 to Windows 10 in 2015. A common explanation is that some software checked for names starting with “Windows 9” to detect Windows 95 and 98, but Microsoft has never confirmed the reason.
Is Windows 11 a new operating system?
No. It is an evolution of the same NT codebase as Windows 10, with a new interface and stricter security requirements.
