Windows 10

Windows 10 is an operating system released by Microsoft in 2015. For pre-release wallpapers, see Windows 10 Technical Preview.

Wallpapers
Chris Raykovich served as the director of 10's wallpapers, while Marylee Johnson served as the executive producer. They decided to hire former National Geographic photographer Steve McCurry to take photos in New Zealand to be used for 10's wallpaper set. They also hired Chad Copeland to take a few photos at Australia and Hawaii. Along with the new wallpapers, the Flowers theme from 8 would be reused yet again. McCurry and Copeland also took several shots that did not make it into the final release, which are present on Raykovich and Johnson's websites.

The default wallpaper was created by a team led by graphic designer Bradley G. Munkowitz. It is included at many different resolutions as low as 1024x768 and as high as 3840x2160. Starting with Windows 10 version 1903 it was replaced with a more simplified version.

Team
The Team edition of 10 contains an entirely different set of wallpapers, all at 3840x2160 as opposed to 1920x1200. They are split into two folders: Cat01 and Cat02. Three of them also appear in other editions of 10 as lock screen wallpapers, but here they are cropped differently and appear less saturated. Most of these are in PNG, resulting in large file sizes.

Lock Screen Wallpapers
McCurry and Copeland were also involved with taking the lock screen wallpapers, except for the last one which is just a single color. This list only includes built-in ones, due to the sheer volume of Spotlight ones.

Team
Team's lock screen wallpapers are also different from other editions of 10, although they are simply reused from the desktop wallpaper themes also present in Team. As with those, three of them also appear in other editions of 10 as lock screen wallpapers, but here they are cropped differently and appear less saturated.

User Account Pictures
Like in 8 and 8.1, Windows 10 has only 2 identical user account pictures, guest and user, used for default accounts and guest account respectively, even though it's impossible to create a guest profile without command prompt and local policy editing since very early Windows 10 builds[exact build?].

Starting from Windows 10 2004, both pictures were changed to fit better with brand new light interface theme, which is now used by default.

Both pictures, just like in Windows 8 and 8.1, have resolution of 448x448px. They also has .png-formatted versions of both of the pictures and 4 resized versions of the user picture, mainly used by UWP apps.

Picture Password
You can see this image in the Picture Password setup tutorial when setting it for the first time: