Windows is an OS developed from Microsoft for the X86 and X64 PC infrastructure.

There are still some other versions but the list would be endless long when I would write every codename Microsoft used as also many projects were never released… 

Codename / Preliminary nameFinal Name
Interface ManagerWin 1.01
SpartaWfW 3.1
NT BetaNT 3.1
DaytonaNT 3.5
Chicago Alpha / Chicago BetasWindows 95
NashvilleWindows 95 B
CairoNT 4.0
MemphisWindows 98
NT 5.0Windows 2000
Neptunenever released / merged to Whistler
GeorgiaWindows ME
WhistlerWindows XP
.NET ServerWindows 2003 Server
Longhorn / Vista BetaWindows Vista
Longhorn ServerWindows Server 2008
 Blackcomb / ViennaWindows 7
Windows Server 8Windows Server 2012
 BlueWindows 8.1
Threshold Server / Windows Server 2015Windows Server 2016
Server 19H1 / Windows Server 2016 R2Windows Server 2019
Threshold (1511) / Redstone

Windows 10

 

Windows 11

There are still some other versions but the list would be endless long when I would write every codename Microsoft used as also many projects were never released… 

2001
25 October 2001

Windows XP

Windows XP

With the 2001 release of Windows XP, Microsoft united its various Windows packages under a single banner, offering multiple editions for consumers, businesses, multimedia developers, and others.

1985
20 November 1985

Windows 1.01

Windows 1.01

Bill Gates said in that time: Windows should be like MAC OS