Halloween DealsAmazon USHalloween week deals: useful picks before month-endAmazon US: current deals, useful picks and tech finds.Check DealsClean PCRecommendedOne scan can reveal what keeps slowing WindowsLook for cleanup and repair opportunities.Run ScanHalloween DealsAmazon USOctober picks are moving - compare before checkoutAmazon US: current deals, useful picks and tech finds.See Picks×
FREEDOM251

Freedom251 › Blog › Desktop Mode

How to Add Non-Steam Games to Steam Deck and Use Proton

By Freedom251 Team · · 9 min read

Free tools Windows power users keep installed

One-click scans. No signup required.

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.

To add a non-Steam game to your Steam Deck, install the game or application first, switch to Desktop Mode, add its executable through the Steam client’s Add a Non-Steam Game command, then return to Gaming Mode. The result is a Steam library shortcut to software already on your drive—not a download, license check, or ownership record.

You can then try Proton for that library entry. Open its properties, go to Compatibility, enable Force the use of a specific Steam Play compatibility tool, and choose a Proton version. This setting is per entry, and it may help a Windows application launch, but it cannot guarantee that a third-party launcher, anti-cheat system, online service, controls or game will work.

As an Amazon Associate I earn from qualifying purchases.

What this process actually does

Steam Deck has two main interfaces. Gaming Mode is the console-like environment used to launch library items, while Desktop Mode provides a Linux desktop and the full Steam client. Adding a non-Steam game connects an application that is already installed on the Deck to your Steam library. Valve describes the result as a shortcut: “This will only add a shortcut to your game in the Steam client.” (Steam Support)

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.

The shortcut can appear in the library’s non-Steam section and can be launched from Gaming Mode, but Steam does not acquire the game, validate a license, or become responsible for delivering its updates. Updates remain the responsibility of the game, launcher or store that supplied the installation. A shortcut also is not proof that you own the software.

#1 Best Overall
Elebase USB to USB C Adapter for iPhone 18 Pro Max,USBC Car Charger Adapter | 4Pack Type C Female to A Male Cable Converter for Apple Duo 17 16 15 14 Plus,iWatch Watch 12 11 10,iPad 9 8 Air,Airpods 5 4
  • Read Before You Buy — No Video Output: These adapters support charging and USB 2.0 data transfer, but cannot transmit video signals. Except for standard USB webcams (which use USB data only), they are not compatible with HDMI/DisplayPort cables, video-capable USB-C hubs, or docking stations with video output.
  • Convert USB-A Ports to USB-C: Designed to connect USB-C earphones, cables, flash drives, card readers, and other USB-C accessories to standard USB-A ports. Plug-and-play with no drivers or software required.
  • Aluminum Alloy Housing: Built with a sturdy aluminum alloy shell that aids in heat dissipation and protects against daily wear and scratches. Designed to maintain a stable and secure connection.
  • Compact & Travel-Friendly: The ultra-compact design allows the adapter to stay plugged into your device without blocking adjacent ports or adding bulk, reducing wear and tear on your original USB ports.
  • 12-Month Warranty: Backed by a 12-month manufacturer warranty for peace of mind. Designed to meet strict quality control standards for reliable everyday performance.

What you need before starting

  • The game or application must already be installed on the Deck, an attached storage device, or another location the Deck can access.
  • You need to be able to open the Steam client in Desktop Mode.
  • If you plan to use Proton, have a particular Proton release in mind only as a starting point; there is no universally best version for every non-Steam title.
  • For extensive desktop work, a physical keyboard and mouse can help. Steam Deck includes trackpads and an on-screen keyboard, but Valve says some situations still require physical peripherals. (Steam Deck and Steam Machine Desktop: FAQ)

Switch to Desktop Mode

  1. Press the Steam button to open the main menu.
  2. Select Power.
  3. Choose Switch to Desktop.

The English-language labels above are Valve’s current labels. SteamOS and Steam client updates can move or rename commands, so look for the equivalent power option that leaves Gaming Mode and opens the desktop. Valve documents this route in its Desktop FAQ. (Valve Steam Support)

After the desktop appears, allow the Steam client a moment to finish loading. You can use the right trackpad as a pointer and the on-screen keyboard for text entry. If a dialog, installer or launcher does not respond well to those controls, connect a USB, Bluetooth or dock-connected keyboard and mouse rather than changing the operating system.

Add the installed program to your Steam library

  1. In Desktop Mode, open the Steam client.
  2. At the lower-left corner of the client, select Add a Game.
  3. Choose Add a Non-Steam Game.
  4. Steam displays applications it can identify. Select the installed game or program and add it to the library.

Valve says the added item appears in the library’s non-Steam area. (Steam Desktop FAQ) The exact list depends on what the client detects on your system. If the intended program is absent, do not assume that a random executable path is an official universal solution: Valve’s cited FAQ does not provide one method that locates every launcher and every installation type.

What’s actually slowing this PC down?

Pick the symptom - the matching free tool is one click away.

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.

If the application is missing from the list

First verify that the installation itself completed and that you can start it in Desktop Mode using the application’s own launcher or file manager. A missing entry is a discovery or installation problem, not a Proton problem. Confirm that the drive containing the installation is mounted and available, then reopen the Add a Non-Steam Game dialog. If the program still does not appear, consult the installer or store’s documentation for how it registers its executable; avoid downloading an untrusted script merely to create a shortcut.

Rank #2
Sale
Anker USB-C Hub, 5-in-1 USB Hub for Laptops, 4K HDMI Multiport Adapter | USB C Dongle with 90W Max Power Delivery, 3×5Gbps USB A Data Ports, for MacBook, Dell, and More (Charger Not Included)
  • 5-in-1 USB-C Hub: Experience comprehensive connectivity featuring a Power Delivery input, two USB-A 2.0 ports, a USB-A 3.0 port, and an HDMI port. (Note: The USB-C power delivery input port is only for connecting an external wall charger to power your laptop and cannot power peripheral devices.)
  • 90W Pass-Through Charging: Achieve optimal charging with 90W pass-through power to your laptop, supported by a total input of 100W, with the hub reserving 10W for operational efficiency. (Note: Wall charger not included.)
  • Quick Data Transfers: Accelerate your productivity with rapid data transfers using a high-speed 5Gbps USB 3.0 port and two 480Mbps USB 2.0 ports.
  • 4K HDMI Display: Enhance your visual experience with a hub capable of delivering 4K resolution at 30Hz in both mirror and extend modes. Please note that this hub is compatible with MacBook (macOS 12 and newer), Windows 10 and 11, ChromeOS, and laptops equipped with DP Alt Mode and Power Delivery. Note: This device is not compatible with Linux.
  • What You Get: Anker USB-C Hub (5-in-1, 4K HDMI), welcome guide, 18-month warranty, and our friendly customer service.

Some software installs multiple components, such as a launcher and a game executable. Add the component you intend to launch and test that component on its own before changing compatibility settings. A shortcut to a launcher will not automatically make every game managed by that launcher visible as a separate Steam entry.

Return to Gaming Mode and launch the shortcut

  1. On the desktop, select the Return to Gaming Mode link. The wording may vary slightly after a client update, but choose the desktop control that returns to the console interface.
  2. Open Library in Gaming Mode.
  3. Find the title in the non-Steam section and select Play.

The first launch is a useful baseline. Run the program without forcing a Proton tool if it is a native Linux application or if its installer already specifies the runtime it needs. Record what happens: whether a window opens, whether the launcher reaches its sign-in screen, whether controls respond, and whether the application closes immediately. Those observations tell you whether the problem is installation, library registration or compatibility.

Force Proton for one non-Steam entry

Proton is Steam Play’s compatibility layer for running many Windows applications on Linux. Steam lets you select a compatibility tool separately for an individual library entry. Valve documents this setting in its software troubleshooting guide. (Steam Deck Software Info & Troubleshooting Guide)

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.
  1. Highlight the non-Steam entry in your Steam library.
  2. Open the entry’s Properties. In Gaming Mode this is normally available from the game’s settings or gear menu; in Desktop Mode it is available from the library context menu.
  3. Select Compatibility.
  4. Enable Force the use of a specific Steam Play compatibility tool.
  5. Choose a Proton version from the list, close the properties window, and launch the entry.

Valve’s troubleshooting advice for a Steam application issue is to try the latest Proton version. Treat that recommendation as a starting point, not a guarantee for a non-Steam title. (Valve Steam Support) If the result is worse, return to Properties > Compatibility, test another available release, or turn off forced compatibility to return to the default behavior.

Rank #3
Sale
Anker USB C Hub, 7in1 Multi-Port USB Adapter, 4K@60Hz USBC to HDMI Splitter | 85W Max PD, 2 USB 3.0 & 1 USBC Data Ports, SD/TF Card Reader, for Laptops/Mac and Other Type C Devices (Charger Not Included)
  • Sleek 7-in-1 USB-C Hub: Features an HDMI port, two USB-A 3.0 ports, and a USB-C data port, each providing 5Gbps transfer speeds. It also includes a USB-C PD input port for charging up to 100W and dual SD and TF card slots, all in a compact design.
  • Flawless 4K@60Hz Video with HDMI: Delivers exceptional clarity and smoothness with its 4K@60Hz HDMI port, making it ideal for high-definition presentations and entertainment. (Note: Only the HDMI port supports video projection; the USB-C port is for data transfer only.)
  • Double Up on Efficiency: The two USB-A 3.0 ports and a USB-C port support a fast 5Gbps data rate, significantly boosting your transfer speeds and improving productivity.
  • Fast and Reliable 85W Charging: Offers high-capacity, speedy charging for laptops up to 85W, so you spend less time tethered to an outlet and more time being productive.
  • What You Get: Anker USB-C Hub (7-in-1), welcome guide, 18-month warranty, and our friendly customer service.

How to judge a Proton choice

There is no evidence in Valve’s support pages for one Proton version that is best for all third-party games. Evaluate each choice against the application’s actual needs:

Check What to observe What a failure suggests
Launch Does the executable open, or does it exit before showing a window? The selected runtime, installation or launcher may be incompatible.
Launcher flow Can you sign in, download required components and reach the game? The launcher itself may need a different runtime or may not support this environment.
Controls and display Do buttons, trackpads, controller mappings, resolution and fullscreen behave as expected? The program may launch successfully but still need a different configuration.
Stability and performance Does it remain responsive during normal play, or crash and stutter? Try another Proton release and retest from the same baseline; do not assume a newer release is always better.
Online and anti-cheat behavior Can the title connect to its service and enter an online session? Anti-cheat, driver or service restrictions can block play even when the game opens.

Change one variable at a time. If you switch Proton versions, keep the same shortcut, installation and launch arguments so that the result is attributable to the runtime change. A successful window does not establish that every mode, update or online feature will continue to work.

Understand Valve’s compatibility labels

Valve’s Deck Verified system uses four broad categories: Verified, Playable, Unsupported and Unknown. Unknown means Valve has not tested the title; it is not a statement that the title definitely fails. The labels are useful context for Steam-distributed games, but they do not convert a manually added shortcut into a tested or supported product. (Steam Support compatibility guide)

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.

A non-Steam application can lack a Deck Verified label entirely. In that case, use the launch, control, stability and online checks above. Do not infer compatibility from a similar title, a launcher’s reputation or the fact that a different Proton release works for another game.

Rank #4
Sale
UGREEN USB to USB C Adapter Combo 4-Pack, 10Gbps USB C Converter Space Gray | Data transfer & Fast charging for MacBook, iPhone 17/16/15, iPad, Samsung Galaxy, Apple Watch
  • Dual Converters, Infinite Potential:Includes 2× USB C male to USB A female adapters and 2× USB A male to USB C female adapters. Perfect for a wide range of uses—tablets with Bluetooth keyboards, expand USB ports on macbook, and more. Two different converters for all your daily needs
  • Next-Level 10Gbps & 3A Charging: No more slow 480Mbps, this usb to usb c adapter has a transfer speed of up to 10Gbps, allowing you to do more transferring in less time. This usb adapter fits both USB A and USB C charger, supporting up to 3A fast charging
  • Upgraded Exquisite Craftsmanship: With an aluminum alloy housing and metal connector, the usbc to usb adapter is extremely durable and sturdy. Rigorously tested to withstand more than 10,000 times of plugging and unplugging, ensuring long-lasting performance
  • Broad Compatible: The usb c to usb adapter widely supports all USB C/ USB A devices like laptops, tablets, cellphones, car chargers, and phone chargers. Such as compatible with MacBook Pro/Air 2023/2022, Thunderbolt 4/3 Devices,Apple MagSafe Watch 9/8/7/SE/Ultra, iPad Pro 2022/2021, Samsung Galaxy S23/S20/S10, and iPhone 17/16/15 Pro. Plug and play
  • Please Note: To reach 10Gbps speed, keep the cable under 3.3 ft. For USB A Male to USB C adapters, try flipping the USB C connector. USB C Male to USB A adapters support bidirectional 10Gbps transfer within 3.3 ft

Separate the three common failure types

The game is not installed or cannot start outside Steam

Open the installer or launcher in Desktop Mode without using the Steam shortcut. If it fails there, adding it to the library cannot repair the installation. Check the original installer’s requirements, available storage and sign-in state. Reinstall or update through the original source when necessary. Steam’s non-Steam feature only registers a path to software that already exists.

The shortcut is present, but the wrong program opens

Launchers often install several executables. A shortcut may point to an updater, helper process or launcher rather than the game itself. Remove or edit the incorrect library entry and add the component you actually intend to run, using the installer’s documented location. Do not replace an executable with an arbitrary file copied from the internet.

The shortcut launches, but the application fails under Proton

Open Properties > Compatibility and test a specific Proton release. Start with the latest Proton that Steam offers, as Valve recommends for Steam application troubleshooting, then compare another release if the result is unstable. A Proton setting cannot bypass a service-level block, unsupported anti-cheat implementation or a launcher that requires unavailable Windows components.

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Support on Ko-Fi

Stability steps Valve recommends

For general Steam Deck software problems, Valve’s troubleshooting guide recommends installing available system updates and restarting the Deck. Complete those steps before drawing conclusions from a single failed launch. (Steam Deck Software Info & Troubleshooting Guide) After the restart, reproduce the same launch sequence and note whether the behavior changed.

Best Value
Sale
Anker USB C Hub, 5-in-1 USBC to HDMI Splitter with 4K Display | 85W Max PD, 1 Powered USB-C 5Gbps & 2 Powered USB-A 3.0 5Gbps Data Ports, for MacBook Pro, MacBook Air, Dell and More (Black)
  • 5-in-1 Connectivity: Equipped with a 4K HDMI port, a 5 Gbps USB-C data port, two 5 Gbps USB-A ports, and a USB C 100W PD-IN port. Note: The USB C 100W PD-IN port supports only charging and does not support data transfer devices such as headphones or speakers.
  • Powerful Pass-Through Charging: Supports up to 85W pass-through charging so you can power up your laptop while you use the hub. Note: Pass-through charging requires a charger (not included). Note: To achieve full power for iPad, we recommend using a 45W wall charger.
  • Transfer Files in Seconds: Move files to and from your laptop at speeds of up to 5 Gbps via the USB-C and USB-A data ports. Note: The USB C 5Gbps Data port does not support video output.
  • HD Display: Connect to the HDMI port to stream or mirror content to an external monitor in resolutions of up to 4K@30Hz. Note: The USB-C ports do not support video output.
  • What You Get: Anker 332 USB-C Hub (5-in-1), welcome guide, our worry-free 18-month warranty, and friendly customer service.
  • Update SteamOS and the Steam client through their normal update controls.
  • Restart the Deck after updates finish.
  • Retest the shortcut before changing several compatibility settings at once.
  • If the application is a Linux desktop program, ensure it is supported by the Arch Linux environment Valve references in its troubleshooting guidance.

These steps address system stability; they do not promise that an unsupported game or online service will become compatible.

Desktop software, Flatpak and update safety

Valve’s Desktop FAQ describes Flatpak as a way to install applications onto the writable portion of the drive, helping keep them separate from SteamOS system files so future SteamOS updates do not break them. The same FAQ warns that software installed outside Flatpak may be wiped by an update and cautions users against running random commands or scripts. (Steam Desktop FAQ)

This matters when the “non-Steam game” is actually a desktop utility, emulator front end or launcher. Prefer the application’s supported packaging method where one exists, keep installers and saves backed up, and do not modify the read-only system image merely to create a library shortcut. The basic add-to-library workflow does not require system-image changes.

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.

Practical workflow for repeatable testing

When you are troubleshooting a difficult title, use a small test record instead of changing settings at random:

  1. Write down the installation source and the exact shortcut you added.
  2. Launch once with the default compatibility behavior and record the result.
  3. If it is a Windows application, force one Proton version and repeat the same action.
  4. Check launch, launcher sign-in, controls, stability and online access separately.
  5. After each Proton change, allow the application to complete its first-run setup before judging later screens.
  6. Keep the version that meets your actual requirement, not simply the one that reaches the first menu.

This approach distinguishes a registration error from a runtime error. It also prevents a launcher update, system update and Proton change from being mistaken for one another.

What adding a non-Steam game does not provide

  • No game delivery: Steam does not download or install the title merely because you add its shortcut.
  • No ownership proof: The library entry does not verify a license or establish that the software was purchased through Steam.
  • No automatic update responsibility: Updates come from the original launcher, store or developer.
  • No compatibility promise: Proton is selectable, but third-party launchers, anti-cheat systems and online services can still fail.
  • No universal executable finder: If Steam does not list the intended program, Valve’s support pages do not specify one guaranteed path for every installer.

Quick decision checklist

  • Is the software already installed and launchable in Desktop Mode?
  • Did you add it through Add a Game > Add a Non-Steam Game?
  • Can you see it in the library’s non-Steam section after returning to Gaming Mode?
  • Did you test the default launch before forcing Proton?
  • If Proton is needed, did you use Properties > Compatibility and change one version at a time?
  • After a failure, did you separate installation, shortcut, launcher, runtime and online-service problems?
  • Have you updated and restarted the Deck before deeper troubleshooting?

The reliable mental model is simple: install the software through its own source, register a shortcut in Steam, then test Proton per entry when a Windows runtime is required. The shortcut makes the program convenient to launch from Gaming Mode; it does not change the software’s ownership, update channel or compatibility obligations.

Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.

Desktop ModeGaming Modenon-Steam gamesProtonSteam DeckSteamOS

Leave a Reply

Your email address will not be published. Required fields are marked *

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.

Recommended PC Tool
Recommended PC Tool
Outdated Drivers Are Slowing You DownFree scan - exact matches
Windows Errors? Fix Them Before They SpreadFree repair scan

Two free Windows tools

One Free Minute Could Fix That PC

Before you go - each of these free tools takes about a minute and tackles what quietly slows a Windows PC down.

Special offer. View Outbyte info, uninstall instructions, EULA, and Privacy Policy.