Microsoft is experimenting with a Steam Deck-friendly “handheld mode” for Windows

But Windows isn't an ideal operating system for the Steam Deck, at least not out of the box. Its mouse-and-keyboard-oriented user interface isn't comfortable or convenient to use on a small handheld system like the Steam Deck. Windows 11 makes some allowances for touchscreens, but its buttons and menus can still be hard to tap on such a small screen. The controller doesn't work outside of Steam, including on Windows' touchscreen keyboard, and installing drivers and launching games for the first time can be a pain.

Microsoft is aware of the problems running Windows on the Steam Deck and other similar handheld Windows PCs, and at least some developers inside the company have spent time thinking of ways to address them. That's the thrust of a leaked presentation (posted in two parts by Twitter user _h0x0d_) about a new Handheld Mode" for Windows, developed as part of an internal Microsoft hackathon in September 2022.

Windows just isn't a great operating system choice for these handheld PC gaming devices, and slapping a skin on it is not going to change that. Valve can integrate Linux and Proton with the hardware of the Steam Deck, and fine tune both down to the very source code - and considering Valve's many contributions to open source, that's exactly what it's doing.

Meanwhile, if you're one of those companies making Steam Deck competitors running Windows - you're shit out of luck. All you can do is add crapware left and right to hide the Windows of it all, but in the end, you just can't optimise the software for the hardware in the same way Valve can.