Windows has practically controlled PC gaming for decades. If you have a gaming computer, there is a high probability that it is running Microsoft's operating system.
But Valve is slowly changing the rules of the game.
SteamOS has grown from a system that most PC players associated exclusively with Steam Deck into a platform that Valve is increasingly expanding to other devices. And it is this trend that could represent one of the first real threats to Windows' dominance in the world of PC gaming.
Windows 11 has a problem that's not just about performance
In recent years, many players have complained about the amount of additional services, applications, background processes, Microsoft accounts, referrals and Windows Update.
Microsoft confirms that Windows 11 automatically downloads and installs available updates, while some updates may require a system restart to complete. Active Hours exist precisely to reduce the possibility of restarts at an inconvenient time.
Windows also uses diagnostic data, while optional telemetry may include information about the use of applications, their launch, usage time and user interaction with certain system functions.
None of this in itself means that Windows is a bad gaming system. The problem for Microsoft is that Valve offers a completely different philosophy.
SteamOS is built around gaming
SteamOS tries to bring the behavior of the computer closer to the console.
Turn on the device, get the Steam interface and start playing. Valve especially highlights functions such as fast suspend/resume system, controller interface and simpler system and game management.
And underneath that simple interface is a Linux desktop, which means that SteamOS is not a locked console but can still function like a classic computer.
That's probably the biggest strength of Valve's idea: the simplicity of a console with the freedom of a PC.
Proton changed Linux gaming
The biggest obstacle to Linux has long been simple: games were made for Windows.
Valve has dramatically changed that situation through Proton.
Windows games that have never received a Linux version can now in many cases be run through Proton without the need for the developer to make a special Linux port.
Even major anti-cheat systems are no longer an automatic obstacle. Valve's documentation lists Proton support for Easy Anti-Cheat and BattlEye, although the game developer still has to enable proper support.
This is where one of SteamOS' biggest remaining problems lies: not every game is compatible.
Certain multiplayer games, anti-cheat implementations, mods, launchers, and specific Windows software can still be a reason for a gamer to stay on Windows.
Valve is no longer making SteamOS just for Steam Deck
This is a part of the story that Microsoft probably needs to look at much more seriously.
At the beginning of 2025, Valve announced the expansion of SteamOS beyond the Steam Deck, and the Lenovo Legion Go S became the first handheld of another company officially licensed for SteamOS. Valve then confirmed that it is also working on increasing compatibility with other handheld computers.
Development has continued throughout 2026. SteamOS upgrades now bring improvements to compatibility with various ASUS, Lenovo, MSI and other devices, while SteamOS 3.9 further improves compatibility with various motherboards and PC configurations.
Valve has also expanded its hardware strategy: the Steam Deck has been joined by the new Steam Machine and Steam Frame, and Valve is officially introducing them as devices that use SteamOS and the Steam ecosystem.
In other words, SteamOS is no longer just an “operating system for the Steam Deck.”
It becomes a platform.
But the numbers still clearly belong to Microsoft
You have to be realistic here.
According to Valve's Steam Hardware & Software Survey for August 2026:
Windows 11 alone is used by about 71% of Steam users. SteamOS Holo currently represents about 21% of Linux users on Steam, or less than one percent of the total Steam base.
So, to say that SteamOS is currently threatening Windows market share would be an exaggeration.
But the potential threat is not today's percentage.
The problem for Microsoft is direction of development.
Microsoft no longer has a completely secure position
Valve controls the largest PC gaming store, develops its own operating system, manufactures gaming hardware and invests in technology that enables playing Windows games without Windows.
That's a very unusual combination.
If SteamOS continues to expand hardware compatibility, Proton continues to improve gaming support, and PC manufacturers start offering SteamOS devices direct from the factory, Microsoft could for the first time have a serious competitor that isn't trying to offer gamers yet another desktop operating system.
Valve offers them something much simpler:
a computer made primarily for gaming.
Windows is not going away. Its compatibility, software ecosystem, and huge user base still represent an advantage that SteamOS won't be able to catch up with anytime soon.
But a few years ago the question was:
"Can you even seriously play on Linux?"
Today the question has become:
"Do I even need Windows for gaming?"
And this is precisely the question that should make Microsoft monitor what Valve is doing very carefully.
