Some Steam Machines come with Windows pre-installed, so you wouldn’t have to put it on the machine.

Actually, it’s a Debian derivative. Ubuntu itself is based on Debian.

I believe this is the configuration he received (the page is currently unavailable from GameStop.com, so I had to use the Wayback Machine): http://www.gamestop.com/pc/consoles/al…

The Alienware Steam Machine only comes with SteamOS. Desktop mode simply accesses the GNOME 3 desktop environment of SteamOS. The Alienware Alpha comes with Windows, and uses Alienware’s Alpha UI, which a modified version of Kodi.

“Every Steam Machine runs SteamOS.” That people are referring to ‘Windows-based Steam Machines’ (as I’ve read numerous similar statements) just goes to show that the Steam Machine brand has already become watered-down and rather meaningless.