Which features of Windows 7 and Windows 8 are not used in Windows 10?

Features of Windows 7 and Windows 8 are not used in Windows 10:

• DX12 will never be available on Windows 7 or Windows 8.Additionally, Windows 10 allows you to stream games from your Xbox One. Xbox One controllers are compatible with Windows 10 PCs, so you can start playing The Witcher 3 right away on your desktop or laptop.
• Windows 8 has a decent online search built into its divisive Start Screen, but Windows 7 only has local searches (what's on the computer), thus Windows 10 clearly outperforms both. Cortana, a voice assistant moved over from Windows Phone and named after the Halo video game franchise, is the key to its success.
• While both Windows 7 and Windows 8 do a decent job of keeping users safe, Windows 10 takes the game to the next level with a number of additional features. The first is 'Device Guard,' which protects against zero-day attacks by validating unsigned software and apps.

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