If you sideload Windows on your Steam Deck, Microsoft is working to make the experience a lot better.
Mockups showing a handheld mode for Windows running on handheld PC devices.

Word from The Verge says that Microsoft is currently experimenting with a new "handheld mode" for Windows. This Windows handheld mode would allow those who install Windows onto devices like the Steam Deck to enjoy a more streamlined experience.

The report from The Verge cites a leaked video that dates back to September 2022. The video is from an internal hackathon at Microsoft and shows off several optimized UI elements for an experimental handheld mode. As this all originates from a hackathon, it is possible that Microsoft could end up greenlighting the idea and ship them to consumers.

That is to say: Nothing about this Windows handheld mode is set in stone just yet. All we know is that Microsoft is at least experimenting with the idea and it could end up shipping in a future Windows update. That, or it may just go absolutely nowhere and you are left with an experience that is far less than optimal when using mobile PC devices like the Steam Deck.

If you have yet to run Windows on something like the Steam Deck, you are missing out on a really awkward experience. For instance, there is little to no controller support in Windows outside of the Steam app and Steam games. The included touch keyboard in Windows is not at all optimized for screen sizes that measure 7 inches. There are also some technical limitations happening behind the scenes as well. Some Windows games simply will not open at all because they don't understand how to handle the Steam Deck's shared memory.

The video references some prototype handheld work created by Dorothy Feng, a senior UX designer at Microsoft. It includes a launcher that can open games from Steam, PC Game Pass, EA Play, Epic Games Store, and more. This handheld gaming prototype also includes a keyboard optimized for the Steam Deck that can be navigated using a controller, and even a floating taskbar that we’ve seen Microsoft tease before.
Outside of the Steam Deck, several of these handheld PC devices rely on Windows for their main operating system. Steam Deck at least has the advantage of a custom designed operating system it can use that was built with handheld use in mind. Should Microsoft push forward with this Windows handheld, alternatives to the Steam Deck will start to look at little more attractive.