Themes: Moving to another operating system...

This theme started life in Windows 10 Technical Preview. It's now also active in Windows 8.1, as you will notice from the lower right corner of the screen. You can do this, by copying from one operating system into another, when both are on the same drive. It's like a built-in 'Home Group' without passwords or log-ins. Because you aren't accessing another computer, just a different part of the same one. So File Explorer does it very nicely. Another reason for dual or triple booting... and three is better than two.