How to Fix the inpoutx64.sys Crash and BugCheck 0x93 on Windows 11 (KB5121003 Fix)

To fix the KB5121003 game crash caused by inpoutx64.sys, open Command Prompt as Administrator and run sc.exe config inpoutx64 start= disabled, followed by sc stop inpoutx64. Next, delete inpoutx64.sys from C:\Windows\System32\drivers\ and restart your PC. This stops BugCheck 0x93 crashes while keeping security updates intact.

Windows 11 cumulative update KB5121003 enforces strict kernel handle validation, causing the legacy inpoutx64.sys port input-output driver to trigger BugCheck 0x93 or game freezes during anti-cheat startup. This conflict affects games that probe low-level hardware registers, including ARC Raiders, The Finals, and MARVEL Tōkon: Fighting Souls.

You can resolve this issue in under three minutes without rolling back critical Windows security patches.

The 30-Second Diagnostic: Verify inpoutx64.sys Is Your Culprit

To confirm inpoutx64.sys is causing your game crashes, open Command Prompt as administrator and execute sc query inpoutx64. If the service is listed as installed or running, or if your minidump shows BugCheck 0x93 (INVALID_KERNEL_HANDLE), inpoutx64.sys is the confirmed cause.

Do not delete system drivers or modify registry keys before verifying that inpoutx64.sys is present on your storage drive. Other anti-cheat conflicts can produce similar launch crashes on modern Windows 11 builds.

Run an elevated service query to check if the driver service is registered:

1. Press the Windows Key, type cmd, right-click Command Prompt, and select Run as administrator.
2. Type sc query inpoutx64 and press Enter.

If the console outputs SERVICE_NAME: inpoutx64 with a state of RUNNING or STOPPED, the driver is installed. If the console displays [SC] EnumQueryServicesStatus:OpenService FAILED 1060: The specified service does not exist, your crashes stem from a different component.

If your computer encountered a Blue Screen of Death, inspect the crash dump directly:

1. Open File Explorer and navigate to C:\Windows\Minidump\.
2. Open the latest .dmp file using WinDbg or a dump analysis tool.
3. Run the command !analyze -v in the analysis console.
4. Check the MODULE_NAME and IMAGE_NAME lines.

If the output lists IMAGE_NAME: inpoutx64.sys alongside DEFAULT_BUCKET_ID: WIN8_DRIVER_FAULT and BUGCHECK_STR: 0x93, the driver attempted an illegal handle operation.

You can also check the Windows Reliability Monitor to confirm user-space crashes:

1. Press Windows Key + R, type perfmon /rel, and press Enter.
2. Select the date and time of the game crash.
3. Review the failure log for your game executable.

Unreal Engine titles report an Application Error showing faulting module inpoutx64.sys with exception code 0xc0000005 (Access Violation) or log a Hang detected on GameThread error.

The table below maps these diagnostic symptoms directly to confirmed root causes.

Also Read: Windows 11 Game Stuttering After an Update

Symptom-to-Fault Confirmation Matrix

This table maps observed game crash symptoms to their technical triggers and targeted fixes.

Observed Symptom	Error Identifier	Underlying Technical Trigger	Confirmed Action
Instant Blue Screen of Death during anti-cheat initialization	BugCheck 0x93: INVALID_KERNEL_HANDLE	The driver passed an invalid or closed handle to the ZwClose system call	Execute Step 1 and Step 2 to remove the service
Game crashes to desktop with Access Violation	Exception Code 0xC0000005	Anti-cheat integrity engine blocked illegal physical memory access	Disable driver startup via sc.exe config
Game freezes at splash screen with GameThread lock	Unreal Engine Hang Detected	The process deadlocked while waiting for an unhandled kernel thread	Terminate the host application and delete the driver
Launcher closes with no error message displayed	Silent Process Termination	Windows protected handle manager terminated the calling process	Clear the service registration and restart Windows

Why Windows 11 KB5121003 Crashes Games on Launch

Cumulative update KB5121003 introduced hardened kernel-handle verification to prevent privilege escalation. When games like ARC Raiders launch, their anti-cheat scans active drivers. When inpoutx64.sys passes an illegal or closed handle to the kernel, Windows enforces a protective 0x93 bugcheck halt.

Windows 11 cumulative update KB5121003 applies to Windows 11 24H2 (OS Build 26100.9168) and Windows 11 25H2 (OS Build 26200.9168). It includes critical security hardening designed to stop local privilege escalation exploits.

Part of this update hardens the Windows Object Manager. The operating system kernel now strictly validates all handle references passed to executive system calls like ZwClose and NtClose.

In previous Windows builds, passing an uninitialized, invalid, or already-closed kernel handle resulted in a silent failure that returned an error status code to the calling driver. Under the updated kernel security baseline, performing an invalid handle operation inside kernel space immediately raises BugCheck 0x93 (INVALID_KERNEL_HANDLE).

The file inpoutx64.sys is an outdated 64-bit kernel-mode port input-output driver originally developed as part of the open-source InpOut32 library. Hardware utilities bundle this binary to directly read and write motherboard hardware registers, SMBus addresses, and sensor microcontrollers.

Because inpoutx64.sys was compiled using legacy driver frameworks, its internal cleanup routines do not conform to modern handle-tracking standards. The driver frequently attempts to release handles that were never opened or tries to close duplicate handles during memory-mapped I/O scans.

When you launch modern titles like ARC Raiders, The Finals, or MARVEL Tōkon: Fighting Souls, their anti-cheat services (including Easy Anti-Cheat and proprietary integrity systems) scan running kernel drivers. This scan queries loaded driver objects to verify system integrity.

When the anti-cheat touches inpoutx64.sys, the driver attempts to close its communication handle incorrectly. The hardened Windows 11 kernel intercepts this invalid operation and forces a protective bugcheck halt to prevent kernel memory corruption.

Titles built on Unreal Engine 5 fail differently if the crash occurs just before kernel panics trigger. The game engine waits for the input-output thread to respond, resulting in an unrecoverable deadlock reported as Hang detected on GameThread.

Step 1: Disable or Remove the inpoutx64 Service via CMD (Recommended Fix)

Disabling the inpoutx64 service prevents the driver from loading into kernel memory at boot. Open Command Prompt as Administrator, execute sc.exe config inpoutx64 start= disabled, then run sc stop inpoutx64 and sc delete inpoutx64. Restart your computer to apply the changes.

Using the Service Controller utility (sc.exe) through an elevated Command Prompt is the safest and most reliable way to neutralize the crashing driver. This approach removes the driver from the Windows boot sequence without damaging operating system components.

Follow this exact command sequence:

1. Press the Windows Key on your keyboard and type cmd.
2. Right-click Command Prompt in the search results and select Run as administrator.
3. If User Account Control asks if you want to allow this app to make changes, click Yes.

First, check that the service exists in the Windows Service Control Manager:

sc query inpoutx64

Next, disable the service so it cannot load during system startup:

sc.exe config inpoutx64 start= disabled

Ensure you include the space between start= and disabled. Without this space, the Service Controller utility will fail to parse the argument and return a syntax error.

Now, attempt to stop the active driver instance in memory:

sc stop inpoutx64

If the console outputs STATE: 1 STOPPED, the driver has unloaded successfully. If the console outputs [SC] ControlService FAILED 1062: The service has not been started, the driver was registered but not actively loaded in memory.

Finally, delete the service registration from the Windows Registry:

sc delete inpoutx64

The console will return [SC] DeleteService SUCCESS. This confirms that Windows has stripped the service entry from HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\inpoutx64.

Restart your computer immediately after completing this command sequence. Rebooting flushes the kernel object table and ensures no lingering threads reference the unloaded driver.

Step 2: Delete Leftover inpoutx64.sys Driver Files

Once the service is deleted, remove the binary from your driver store to prevent re-registration. In an elevated Command Prompt, execute del C:\Windows\System32\drivers\inpoutx64.sys. If the file is locked, reboot your PC into Safe Mode before running the delete command.

Deleting the service registration prevents Windows from starting the driver, but the physical file inpoutx64.sys remains on your hard drive. Leaving this file in your driver directory allows third-party hardware monitoring tools to reinstall the service during automatic background updates.

To delete the physical driver file using Command Prompt:

1. Open Command Prompt as administrator.
2. Execute the following file deletion command:

del /f /q C:\Windows\System32\drivers\inpoutx64.sys

The /f parameter forces the deletion of read-only files, while /q enables quiet mode to suppress confirmation prompts.

[Image 5: File Explorer navigating to C:\Windows\System32\drivers\ selecting inpoutx64.sys | Alt: Locating inpoutx64.sys file in System32 drivers folder]

You can also delete the file using the File Explorer graphical interface:

1. Press Windows Key + E to open File Explorer.
2. Navigate to C:\Windows\System32\drivers\.
3. Scroll through the directory and locate inpoutx64.sys.
4. Select the file and press Shift + Delete to permanently remove it.
5. Provide administrator confirmation when prompted by the operating system.

Resolving “Access Denied” and File Lock Errors

If File Explorer reports that the action cannot be completed because the file is open in another program, a background hardware utility is actively holding an open file handle on the driver.

Do not attempt to alter folder permissions or change file ownership in C:\Windows\System32\drivers\. Instead, terminate the host process locking the file.

1. Press Ctrl + Shift + Esc to open Task Manager.
2. Look through Background processes for software like Razer Synapse, Razer Update Tool, ASUS Armoury Crate, MSI Center, or ZenTimings.
3. Right-click the parent process and select End task.
4. Retry the file deletion command in your elevated Command Prompt.

If the file remains locked by a kernel process, boot Windows into Safe Mode to release all third-party handles:

1. Hold the Shift key on your keyboard while clicking Restart in the Windows Start menu.
2. Navigate to Troubleshoot, select Advanced options, click Startup Settings, and click Restart.
3. When the startup options menu appears after rebooting, press 4 or F4 to select Enable Safe Mode.
4. Log into Windows, open Command Prompt as administrator, and run the deletion command again.
5. In Safe Mode, third-party services do not initialize, allowing you to delete the file without access conflicts.

After deleting the file, inspect the Windows Registry to ensure no orphaned configuration keys remain:

1. Press Windows Key + R, type regedit, and press Enter.
2. Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\.
3. Scroll through the keys to confirm that the inpoutx64 folder is completely gone.
4. If the key still exists, right-click inpoutx64, select Delete, and confirm the prompt.

Step 3: Identify and Update Conflicting Hardware Utilities

Deleting inpoutx64.sys may temporarily disable features in older hardware utilities that installed it. Identify host applications—such as Razer Update Tool, ZenTimings, or ASUS Aura Sync—and update them to modern versions that utilize updated, WHQL-compliant hardware monitoring drivers instead of legacy InpOut libraries.

The inpoutx64.sys driver does not ship natively with Windows 11. It is dropped onto your system by third-party motherboard tools, peripheral installers, and memory diagnostics software.

If you delete the driver file without updating or reconfiguring the parent utility, that application may crash or recreate the driver binary the next time it runs.

The table below details the most common utilities that deploy inpoutx64.sys, their file locations, and the permanent resolution for each tool.

Conflicting Hardware Utilities and Long-Term Solutions

This table lists third-party utilities that bundle the legacy driver along with their installation paths and verified update paths.

Utility Name	Primary Purpose	Common File Installation Path	Safe Resolution
Razer Update Tool	Firmware and component installer for Razer peripherals	C:\Program Files (x86)\Razer\Update Tool\	Update via Razer Synapse 4; newer updater versions use modern kernel APIs
ZenTimings	Memory timing and sub-timing monitoring for AMD Ryzen CPUs	Standalone executable directory and local temp extraction	Update to version 1.3.2 or newer, which removes raw port I/O dependencies
ASUS Aura Sync / Armoury Crate	Motherboard RGB lighting and sensor control	C:\Program Files\ASUS\Aura\ or Armoury Crate folders	Run Armoury Crate Uninstall Tool, reboot, and install the latest package
MSI Center / Dragon Center	Motherboard telemetry, fan curves, and LED control	C:\Program Files (x86)\MSI\MSI Center\	Update MSI Center via the Microsoft Store to pull updated SDK drivers
Legacy Corsair Utility Engine	Peripheral lighting profiles and legacy fan controllers	C:\Program Files\Corsair\Corsair Utility Engine\	Upgrade to Corsair iCUE 5.x, which purges obsolete low-level access drivers

Managing Razer Update Tool and Peripheral Updaters

The Razer Update Tool is one of the most common applications that deploys inpoutx64.sys on modern gaming PCs. Older versions of this installer drop the driver into C:\Windows\System32\drivers\ to query hardware registers on external docks and mouse dongles.

Open File Explorer and check if you have a folder at C:\Program Files (x86)\Razer\Update Tool\. If present, check the folder contents for inpout32.dll or inpoutx64.sys.

Launch Razer Synapse and check for pending application updates. Modern builds of Razer Synapse 4 have phased out InpOut dependencies in favor of standard Windows Driver Framework interfaces.

If your Razer software does not offer an update, uninstall the standalone Razer Update Tool from Settings under Installed apps. Your mice, keyboards, and headsets will continue to function normally using standard USB Human Interface Device drivers.

Resolving ZenTimings Incompatibilities

ZenTimings is a popular portable utility used by PC enthusiasts to read memory timings, voltages, and Infinity Fabric speeds on AMD Ryzen systems. Older builds of ZenTimings relied on InpOutx64 to read memory controller registers directly from the processor SMBus.

If you run ZenTimings, check your application version. Versions older than 1.3.0 extract inpoutx64.sys into your temporary directory and register the service dynamically every time the application launches.

Download the latest release of ZenTimings from its official repository. Modern builds use updated memory-mapped access methods that work within Windows 11 virtualization boundaries without triggering handle violations.

If you no longer actively tune your memory timings, delete the extracted ZenTimings folder completely to prevent accidental execution.

What Is Microsoft’s Automated Fix (Known Issue Rollback)?

Microsoft deployed an automated Known Issue Rollback (KIR) on August 26, 2026, which blocks inpoutx64.sys from loading on unmanaged consumer PCs without requiring manual file deletion. Enterprise-managed systems require administrators to set the registry value Start to 4 under the inpoutx64 service key.

Following reports from game developers like Embark Studios, Microsoft initiated an automated driver block via its Known Issue Rollback (KIR) mechanism on August 26, 2026, starting at 6:00 PM Pacific Time.

A Known Issue Rollback allows Microsoft to disable a problematic operating system behavior without uninstalling the broader security update. In this case, Microsoft pushed an updated kernel driver block rule that prevents inpoutx64.sys from initializing on startup.

For unmanaged consumer home PCs running Windows 11 Home or Windows 11 Pro, this rollback propagates automatically through Windows Update background telemetry. It can take up to 24 hours for the policy change to reach your machine.

You can verify if the automated block is active on your PC:

1. Open Command Prompt as administrator.
2. Type sc query inpoutx64 and press Enter.
3. If the state reports STOPPED and attempting to run sc start inpoutx64 returns Access is denied or This driver has been blocked from loading, the automated rule is active.

Restarting your computer once or twice helps accelerate the application of new Group Policy and KIR definitions delivered by Windows Update.

Enterprise and Domain Configuration Fix

On enterprise-managed PCs connected to an Active Directory domain or managed via Microsoft Intune, automated KIR definitions do not apply automatically. IT administrators must deploy a specific registry policy to disable the driver service across their fleet.

Administrators can deploy this change using Command Prompt or Group Policy:

reg add "HKLM\SYSTEM\CurrentControlSet\Services\inpoutx64" /v Start /t REG_DWORD /d 4 /f

Setting the Start DWORD value to 4 configures the driver startup type to Disabled. This stops the driver from executing during boot while keeping the update package intact across all client workstations.

Microsoft confirmed that permanent handle compatibility adjustments are integrated into the September 2026 Patch Tuesday cumulative update.

Workaround: Rolling Back Windows Update KB5121003 (And the Security Tradeoff)

If games still crash and driver removal fails, you can uninstall KB5121003 via Settings > Windows Update > Update history > Uninstall updates. However, this removes critical security patches for 400+ vulnerabilities, including the LegacyHive zero-day. Use this strictly as a temporary last resort.

Uninstalling the entire cumulative update will stop BugCheck 0x93 crashes by returning your kernel to the pre-August handle validation state. However, doing so carries significant security risks that every user must understand.

The Security Tradeoff: The LegacyHive Vulnerability

Cumulative update KB5121003 is not an optional preview patch. It is the mandatory August 11, 2026 Patch Tuesday security baseline.

This update patches more than 400 documented Common Vulnerabilities and Exposures (CVEs). Most importantly, it patches an active zero-day vulnerability known as LegacyHive.

The LegacyHive vulnerability allows malicious local processes to bypass Windows security boundaries and execute arbitrary code with SYSTEM privileges. Removing KB5121003 unpatches this vulnerability, leaving your computer susceptible to credential theft and privilege escalation attacks.

Always attempt the manual driver removal steps in Step 1 and Step 2 before considering an update rollback. Removing inpoutx64.sys eliminates the crash entirely while keeping your system protected against critical security vulnerabilities.

How to Uninstall KB5121003 via Windows Settings

If you must roll back the update as a temporary diagnostic measure, use the Windows graphical interface:

1. Press Windows Key + I to open Settings.
2. Select Windows Update from the left navigation menu.
3. Click Update history, scroll to the bottom of the page, and select Uninstall updates.
4. Locate Security Update for Microsoft Windows (KB5121003) in the list.
5. Click the Uninstall button next to the entry.
6. Confirm the prompt when Windows asks if you are sure you want to remove the update.
7. Allow the uninstallation process to finish, then restart your computer.

How to Force Update Removal via Command Line

If the Settings interface fails or hangs during removal, use the Windows Update Standalone Installer (wusa.exe) from an elevated Command Prompt:

wusa /uninstall /kb:5121003 /quiet /norestart

The /quiet flag executes the removal process in the background, while /norestart prevents an unexpected system reboot.

Wait approximately three to five minutes for the command to finish executing in the background. Once the command prompt returns to an active cursor line, manually restart your PC:

shutdown /r /t 0

Pausing Updates to Prevent Automatic Reinstallation

Windows Update runs automated background scans and will attempt to reinstall KB5121003 within twenty-four hours. You must pause updates to prevent the operating system from redownloading the patch.

1. Open Settings and select Windows Update.
2. Find the Pause updates section.
3. Click the Pause for 1 week drop-down menu and select Pause for 5 weeks.

Pausing updates gives third-party hardware vendors time to release updated drivers before Windows reapplies cumulative security patches.

Troubleshooting: What to Do if Deletion Fails or the System Won’t Boot

If your computer fails to boot or encounters recurring Blue Screens of Death after removing system files, use native Windows Recovery Environment (WinRE) utilities to restore stability.

Deleting inpoutx64.sys cannot damage the core Windows operating system because it is a third-party non-boot driver. However, if a user accidentally deletes valid system files or modifies incorrect registry keys, Windows may enter an automatic repair loop.

Booting into the Windows Recovery Environment

If your system crashes repeatedly during the boot sequence:

1. Power on your computer. As soon as the Windows boot circle appears, press and hold the physical power button for five seconds to force a hard shutdown.
2. Repeat this process two consecutive times.
3. On the third boot, Windows will display Preparing Automatic Repair and launch the Windows Recovery Environment.
4. Select Advanced options on the initial repair screen.
5. Click Troubleshoot, then select Advanced options.

Restoring the System via System Restore

If you created a restore point prior to troubleshooting, rolling back your system state restores default drivers without affecting personal files:

1. From the Advanced options menu in WinRE, select System Restore.
2. Choose your administrative account and enter your password.
3. Select the restore point created immediately before the installation of update KB5121003 or before your manual registry changes.
4. Click Next, then click Finish to begin the restoration process.
5. The system will restore registry hives and reboot into a stable desktop state.

Deleting Locked Drivers via WinRE Command Prompt

If you cannot delete inpoutx64.sys inside Windows because it is locked by active services, remove it directly from the WinRE command console:

1. In the Advanced options menu of WinRE, click Command Prompt.
2. In the recovery console, drive letters often shift. Identify your primary Windows installation drive by typing dir C:\Windows or dir D:\Windows.
3. Assuming your Windows installation is on drive C:, execute the deletion command directly against the driver path:

del C:\Windows\System32\drivers\inpoutx64.sys

4. Type exit and press Enter to close the recovery console.
5. Click Continue to exit recovery and boot into normal Windows 11.
6. Because WinRE does not load third-party driver services, the file will be deleted instantly without access restrictions.

Frequently Asked Questions

What is inpoutx64.sys and is it a virus?

The file inpoutx64.sys is not a virus. It is a legitimate, open-source 64-bit hardware input-output driver bundled by third-party utilities like Razer Update Tool, ZenTimings, and motherboard RGB software to access physical hardware registers.

Does deleting inpoutx64.sys break my RGB lighting?

Deleting inpoutx64.sys will not turn off your RGB lighting. Basic lighting profiles stored on device hardware remain active, though legacy software that relies on outdated InpOut libraries may fail to read motherboard temperatures or synchronize dynamic LED zones until updated.

Why does Arc Raiders crash with BugCheck 0x93?

ARC Raiders crashes with BugCheck 0x93 because its anti-cheat engine scans kernel drivers during launch. When this scan encounters inpoutx64.sys, the driver attempts an illegal handle closure, causing the hardened Windows 11 kernel to trigger an immediate INVALID_KERNEL_HANDLE halt.

Will Microsoft release a permanent fix for KB5121003 game crashes?

Yes. Microsoft deployed an automated Known Issue Rollback on August 26, 2026, to block the driver on consumer systems, and has integrated permanent driver compatibility rules into the September 2026 Patch Tuesday cumulative update.

Can I just disable inpoutx64.sys in the registry instead of deleting it?

Yes. You can disable the driver without deleting the physical file by running reg add "HKLM\SYSTEM\CurrentControlSet\Services\inpoutx64" /v Start /t REG_DWORD /d 4 /f in an elevated Command Prompt. Setting the value to 4 prevents the driver from loading into memory.