Windows 11 KB5121003 Crashing Games? Here's the Fix

If a game started crashing with an "EXCEPTION_ACCESS_VIOLATION" error right after your PC installed the August 2026 Windows update, you're not imagining it. Microsoft confirmed the update is the cause, and a working fix exists today, without waiting for a patch.

What Is Causing Windows 11 Games to Crash After KB5121003?

KB5121003, the Patch Tuesday update Microsoft released on August 11, 2026 for Windows 11 24H2 and 25H2, conflicts with a driver called inpoutx64.sys. This driver ships inside many RGB lighting and peripheral control utilities from keyboard, mouse, and motherboard makers, where it handles low-level hardware port access.

Once the update installs, games touching this driver, either directly or through the peripheral software running in the background, start crashing to desktop, freezing, throwing an EXCEPTION_ACCESS_VIOLATION error, or in some cases triggering a full system restart mid-session. Coverage of the bug named ARC Raiders, MARVEL Tōkon: Fighting Souls, and The Finals specifically, though the underlying conflict isn't limited to those three titles. Any game reading input from a peripheral running inpoutx64.sys is a candidate.

Microsoft acknowledged the issue publicly and said its team is investigating, but as of this writing the official KB5121003 support page still doesn't list it as a known issue. No release date for a permanent, built-in fix has been announced, so the workaround below is currently the fastest path back to stable gaming.

How Do You Know If This Is Your Problem?

Three things point to this specific bug: your Windows build number, your update history, and whether any RGB or peripheral control software runs on your PC.

Open Settings > System > About and check the Windows specifications section. Affected builds are 26200.9168 (Windows 11 25H2) and 26100.9168 (Windows 11 24H2). Next, open Settings > Windows Update > Update history and confirm KB5121003 installed on or after August 11, 2026. Finally, look at what runs in your system tray. Software from Corsair, Razer, Logitech, SteelSeries, ASUS, MSI, or Gigabyte controlling RGB lighting, fan curves, or macro keys is the common thread behind nearly every reported case.

If crashes began right after this update, and one of those utilities runs on your machine, the fix below applies to you directly.

How Do You Fix EXCEPTION_ACCESS_VIOLATION Crashes From KB5121003?

Stop and delete the inpoutx64 driver through Command Prompt. This removes the exact component causing the conflict, without uninstalling the Windows update itself or your peripheral software.

1. Press the Windows key, type cmd, right-click Command Prompt, and select Run as administrator.
2. Enter the following command and press Enter:

   sc stop inpoutx64
   

3. Enter this command and press Enter:

   sc delete inpoutx64
   

4. Open File Explorer and navigate to C:\Windows\System32\drivers.
5. Locate inpoutx64.sys and delete it. If Windows reports the file is in use, restart your PC first, then delete it before launching any games or peripheral software.
6. Restart your PC.

Launch the game previously crashing and test it. Most people who tried this workaround report the crashes and EXCEPTION_ACCESS_VIOLATION errors stop right away, with no other change to system behavior.

If your PC has more than one peripheral or hardware utility installed, run sc query inpoutx64 first to confirm the driver is registered on your system before deleting anything. An empty or "service does not exist" result means this specific driver isn't the source of your crash, and your issue has a different cause worth troubleshooting separately, such as outdated GPU drivers or a corrupted game install.

What Do You Lose By Removing the Driver?

Hardware-level control features tied to this driver stop working, mainly RGB lighting effects and, on some setups, custom fan curves managed through the peripheral software's app. The peripheral software itself still opens and runs normally. Key remapping and other software-level settings typically keep working; only the low-level hardware access tied to inpoutx64.sys stops functioning.

Weigh this trade-off before proceeding. If lighting control matters more to you right now than the affected games, skip this step and wait for Microsoft's official patch instead.

What If You Don't Want to Touch System Drivers Directly?

Uninstall the peripheral or RGB control software bundling inpoutx64.sys, rather than manually deleting the driver file yourself. Go to Settings > Apps > Installed apps, find the RGB lighting or hardware control utility (Corsair iCUE, Razer Synapse, Logitech G HUB, and ASUS Armoury Crate are common culprits), and uninstall it. Doing so typically removes inpoutx64.sys along with the rest of the application.

This route takes longer, since it also removes the software's other features, including macro profiles and saved lighting presets, but it avoids editing system files directly. Choose this option if running Command Prompt as administrator makes you uneasy.

Should You Uninstall KB5121003 Instead?

Uninstalling the update removes August's security fixes along with the gaming bug, including a patch for an actively exploited privilege escalation flaw in the Windows Ancillary Function Driver for WinSock. Giving up this protection isn't worth it for most people, since the driver fix above resolves the crash without touching the update.

If you still prefer rolling back, go to Settings > Windows Update > Update history > Uninstall updates, find KB5121003, and select Uninstall. Windows prompts you to restart afterward. Your PC runs without August's security fixes until you reinstall the update later, so treat this as a short-term option only, not a permanent solution.

How Do You Report This to Microsoft?

Submit crash details through the Feedback Hub app, giving Microsoft's investigation more data to work from. Open Feedback Hub, select Report a problem, choose Gaming > PC Gaming, and describe the crash, including the game name and the exact EXCEPTION_ACCESS_VIOLATION error text, noting it started after installing KB5121003. Attach the crash log if the app prompts for one.

Microsoft tracks reports through Feedback Hub and Windows Release Health, and detailed submissions from affected users help move a permanent fix up the priority list.

Will This Bug Show Up Again With Future Windows Updates?

It's possible, since inpoutx64.sys is a widely reused component across the peripheral hardware industry, not something unique to one vendor. Any future Windows update touching low-level driver signing or kernel access rules carries some risk of tripping a similar conflict for the same reason.

Two habits reduce your exposure going forward. First, keep your peripheral or RGB control software updated directly through the vendor's own updater, since vendors sometimes patch driver compatibility issues before Microsoft does. Second, check the Windows Release Health dashboard at aka.ms/windows11releasehealth before installing a major update on a gaming-focused PC, since Microsoft lists confirmed known issues there once enough reports come in.

If you manage more than one gaming PC, a quick precaution is worth adding to your update routine: test a new cumulative update on one machine before rolling it out everywhere, especially close to a big game launch or tournament weekend.

Key Takeaways

• KB5121003 (Windows 11, August 11, 2026) conflicts with the inpoutx64.sys driver bundled in many RGB lighting and peripheral control utilities.
• The conflict causes EXCEPTION_ACCESS_VIOLATION crashes, freezes, and unexpected restarts in some games, including ARC Raiders, MARVEL Tōkon: Fighting Souls, and The Finals.
• Stopping and deleting inpoutx64.sys via Command Prompt fixes the crashes for most affected users, at the cost of losing RGB or fan-control features tied to this driver.
• Uninstalling your peripheral control software achieves the same fix without editing system drivers directly.
• Rolling back KB5121003 works but removes the update's security fixes, including a patch for an actively exploited vulnerability, so it isn't the recommended long-term fix.