When Microsoft releases Windows 10 next week it will be far from the first glimpse of the operating system.
The OS has grown up in public, with early builds of Windows 10 made available from October last year as part of the Windows Insider Program.
Using feedback from more than five million testers, Microsoft tweaked and added to the operating system - which today looks and feels quite different to the initial release.
This is how Windows 10 evolved from a prototype to the OS that will be released next week.
The first release
The first build of Windows 10 may have looked quite different, but it did feature the reassuring return of the Start menu.
Microsoft is hoping that reinstating the old favorite of Windows owners - whose disappearance in favor of a tile-based Start screen caused consternation in Windows 8 - will win back disgruntled users.
Here you can see the All Apps list, a customisable selection of commonly used apps and the Live Tiles - tiles linking to apps that display dynamically updating information.
Later versions of Windows changed the look and functionality of the Start menu but kept the Live Tiles.