SteamFSE

A lightweight Windows 11 Full Screen Experience (FSE / Xbox Mode) home launcher that starts Steam directly in Big Picture / Gamepad UI.

SteamFSE is designed for Windows gaming handhelds where you want Steam to feel like the native console interface without displaying an additional launcher UI between Windows FSE and Steam.

Visible boot flow

Windows → Full Screen Experience → Splash / Custom Video → Steam Big Picture

Features

• Registers as a selectable Windows 11 Full Screen Experience home app
• Launches Steam directly in Big Picture / Gamepad UI
• Fully releases the startup splash/media UI after Steam becomes ready
• Continues as a lightweight headless FSE home-shell bridge
• Improved Steam foreground and focus handling
• Improved Full Screen Experience / Home activation behavior
• Home activation returns directly to Steam Gamepad UI without recreating the startup splash
• Optional user-supplied custom boot video
• Static splash image fallback
• Automatic video looping while Steam is loading
• Smooth fade transition into Steam Big Picture
• Installation, uninstall, diagnostics, and splash-management helpers included
• Runtime logging for troubleshooting

Tested

SteamFSE v0.2.3 has been successfully tested on:

• ONEXPLAYER X2 Mini Pro
• Windows 11 Full Screen Experience / Xbox Mode

Verified functionality includes:

• Startup into Steam Big Picture
• Static and custom video splash handling
• Controller input
• Full Screen Experience / Home button behavior
• Returning to Steam Gamepad UI
• Extended use after startup

Other Windows 11 gaming handhelds with compatible Full Screen Experience support may also work, but have not yet been personally verified.

Requirements

• Windows 11 24H2 or later
• Windows build 26100 or newer
• Windows Full Screen Experience / Xbox Mode available on the device
• Steam installed and signed in at least once
• Windows Developer Mode enabled during installation
• x64 Windows

Installation

1. Download the latest release ZIP from the Releases page.

2. Extract the ZIP completely.

3. Enable Developer Mode in Windows Settings.

4. Run:

   Install-SteamFSE.cmd

5. Open:

   Settings → Gaming → Xbox Mode / Full Screen Experience

6. Set:

   Home app → Steam FSE

7. Enable:

   Enter Xbox Mode at startup

8. In Steam, disable:

   Run Steam when my computer starts

9. Reboot.

If you are currently using another FSE launcher, keep it installed until SteamFSE has been successfully tested on your device.

Custom Boot Animation

SteamFSE does not bundle any Steam Deck startup video.

Option A — Before installation

Place your own MP4 next to the installer and rename it exactly:

Splash.mp4

Then run:

Install-SteamFSE.cmd

Option B — After installation

Run:

Set-SplashVideo.cmd

and select your MP4.

To remove the custom video and return to the included static image, run:

Remove-SplashVideo.cmd

Recommended video format

• MP4 container
• H.264 video
• AAC audio
• Short startup animation recommended

The video loops while Steam loads. When Steam Big Picture is detected, SteamFSE brings Steam to the foreground and fades the splash away.

Static Splash

If no Splash.mp4 exists, or media playback fails, SteamFSE automatically uses the included:

Splash.png

How It Works

SteamFSE registers itself as a Windows Gaming Full Screen Experience home application.

When Windows activates SteamFSE:

1. SteamFSE displays the static splash or user-provided boot video.
2. Steam is started with Gamepad / Big Picture UI.
3. SteamFSE waits for the Steam interface to become ready.
4. The startup media UI is fully released.
5. Steam is brought to the foreground.
6. SteamFSE continues only as a lightweight headless FSE home-shell bridge.

If the FSE Home action is triggered again, SteamFSE requests the existing Steam instance to return to Gamepad UI without recreating the startup splash.

Troubleshooting

Installer logs:

• SteamFSE_Install.log
• SteamFSE_Compile.log

Runtime log:

%LOCALAPPDATA%\SteamFSE\SteamFSE_Runtime.log

A diagnostic helper is also included:

Diagnose-SteamFSE.ps1

Upgrade

Existing SteamFSE users can:

1. Download the latest PUBLIC ZIP.
2. Extract it completely.
3. Run Install-SteamFSE.cmd.

The installer replaces the previous SteamFSE package.

Uninstall

Before uninstalling SteamFSE:

1. Change the Windows FSE home app back to Xbox or another launcher.

2. Run:

   Uninstall-SteamFSE.cmd

License

SteamFSE is released under the MIT License.

See LICENSE for details.

Acknowledgements

SteamFSE was developed and tested by ND091024, with development assistance from ChatGPT by OpenAI.

ChatGPT was used to assist with implementation, debugging, documentation, and packaging. Final hardware testing, configuration decisions, and release validation were performed by the project author.

Disclaimer

SteamFSE is an independent, unofficial community project provided "as is", without warranties of any kind, express or implied.

Use SteamFSE entirely at your own risk.

SteamFSE interacts with Windows configuration related to Developer Mode, AppX package registration, and Windows Gaming Full Screen Experience (FSE / Xbox Mode). Installation, configuration changes, Windows updates, Steam updates, device firmware, drivers, or third-party software may cause unexpected behavior.

Possible issues may include, but are not limited to:

• Steam or Full Screen Experience failing to start as expected
• Login, startup, or home-app configuration issues
• Application crashes or loss of application settings
• Compatibility problems after Windows, Steam, firmware, or driver updates
• Other unintended system or software behavior

Users should understand the installation and recovery procedures before installing SteamFSE and are encouraged to maintain appropriate backups or system recovery options.

Compatibility is not guaranteed on every Windows device. The project has been personally tested on the ONEXPLAYER X2 Mini Pro, but successful operation on other devices, Windows builds, or future software versions cannot be guaranteed.

To the maximum extent permitted by applicable law, the project author and contributors shall not be liable for any direct, indirect, incidental, special, consequential, or other damages arising from the use of, inability to use, installation of, or modification of SteamFSE, including but not limited to loss of data, loss of settings, system downtime, or software/device malfunction.

Trademarks and Affiliation

SteamFSE is not affiliated with, sponsored by, endorsed by, authorized by, or supported by Valve Corporation, Microsoft Corporation, or ONEXPLAYER.

References to Steam, Windows, Xbox, ONEXPLAYER, and specific hardware models are used solely to describe software compatibility, functionality, or tested hardware.

Steam and the Steam logo are trademarks and/or registered trademarks of Valve Corporation in the U.S. and/or other countries.

Steam Deck is a trademark of Valve Corporation.

Windows and Xbox are trademarks of Microsoft Corporation.

ONEXPLAYER and ONEXPLAYER product names are trademarks or product names of their respective owners.

All other trademarks are the property of their respective owners.

Please do not contact Valve, Microsoft, or ONEXPLAYER for support regarding SteamFSE. Issues related to SteamFSE should be reported through this GitHub repository.

Custom Media

SteamFSE does not distribute or include Steam Deck startup animations or other copyrighted Valve video content.

The optional Splash.mp4 feature is provided only so users can supply their own media.

Users are solely responsible for ensuring that they have the necessary rights or permissions to use and distribute any custom images, videos, audio, logos, or other media they add to SteamFSE.