Windows 2000 was codenamed Utopia. It just isn't known publicly for some odd reason.
Windows 93 is really hard to prove but it was actually Windows Chicago which is the codename for Windows 95 and the earlier version for 95. Windows 97 and 99 was real but it got canceled. Windows 97 was NT 4.0 or 5.0. And Windows 99 got canceled because Microsoft moved on to Windows 2000.
durango
The codename for windows 8 is "Blue".
Whistler.
Longhorn
The code names "Vienna" and "Blackcomb" were both given to Windows 7.
Whistler.
Windows NT 4 did not have a specific codename. The changes between it and Windows NT 3.51 (codenamed Daytona) were mainly just a shell update. The shell update was created as part of the Cairo project.
Windows vista was introduced in July 22, 2005. It is known by its codename 'longhorn' .
7.0 was with Windows 95, and Windows 95A 7.1 is Windows 95B
Windows 95 to Windows 98, and then to Windows XP
Windows 95 was released worldwide.