“Please unload MsIo64.sys before starting the game”: fix it safely
✓ Published July 28, 2026 · Reviewed July 28, 2026The launch error “Please unload MsIo64.sys before starting the game” normally means the game's anti-cheat detected a third-party kernel driver that it will not allow beside the protected game. The message can appear with Easy Anti-Cheat or as an EA Javelin anticheat “incompatible driver” warning. It does not, by itself, mean that you are banned, that the game files are corrupt, or that the named driver is malware.
The safe solution is to identify the hardware utility that installed the exact file, update or cleanly uninstall that utility, restart Windows, and then retest. Do not begin by deleting a file from C:\Windows\System32\drivers.
Avoid the common “rename the .sys file” shortcut. Renaming or deleting a kernel driver by hand can leave its service or hardware utility broken, and disabling Memory Integrity, Secure Boot, the Microsoft vulnerable-driver blocklist, or anti-cheat lowers protection. Update or remove the owning utility through its supported installer instead.
Safe-order checklist
- Record the complete error, anti-cheat name, filename, and path
- Restart Windows once and test again
- Use the file's Properties to identify its publisher and product
- Update Windows and the owning hardware utility from official sources
- Restart and launch the game with anti-cheat still enabled
- If necessary, cleanly uninstall the old utility and restart
- Repair the game's anti-cheat only after the driver conflict is gone
- Escalate to the utility or PC maker if the driver returns
Match your message before changing anything
| What appears | What it usually means | Best first move |
|---|---|---|
| Easy Anti-Cheat: “Please unload MsIo64.sys before starting the game” | EAC has stopped the launch while the named third-party driver is present or loaded | Identify and update the utility that owns the driver |
| EA Javelin anticheat: incompatible driver, often with error 119 | EA has placed the named software or driver on its security blocklist | Update or disable the owning software using the manufacturer's method, then restart |
| Windows Security: “A driver can't load on this device” | Memory Integrity or another Windows protection is blocking an incompatible driver | Keep the protection on if possible; update or remove the app that installed the driver |
| A blue-screen dump mentions MsIo64.sys | This is a system-stability investigation, not only a game-launch block | Preserve the dump and use an evidence-led crash diagnosis; do not delete the named file on assumption |
| The game fails without naming MsIo64.sys | A different launch problem may be responsible | Use the exact error code or a general game-launch guide instead of applying this fix |
What is MsIo64.sys—and is “Mslo64.sys” the same thing?
MsIo64.sys is a third-party kernel driver used by some motherboard, RGB-lighting, sensor, and hardware-monitoring utilities. The filename alone does not reliably identify which application installed your copy. The U.S. National Vulnerability Database documents older MsIo64.sys versions in both MSI Dragon Center and ASUS Aura Sync. That is why guessing from the letters “MSI” can send you to the wrong vendor.
The middle characters are also easy to misread in some fonts: MsIo64.sys uses a capital I followed by a lowercase o. Users often search for Mslo64.sys with a lowercase l. Windows filenames are not case-sensitive, but I and l are different characters. Copy the name and path from the actual message or file Properties rather than retyping it from memory.
Anti-cheat and Windows security tools block certain low-level drivers because kernel drivers have powerful access. A block is not proof that the file is malicious; it means the detected version or behavior does not meet that protection's compatibility or security rules. The supported answer is an updated driver or removal of the software that needs it—not weakening the protection.
Fix the MsIo64.sys game launch error
Record the exact error and restart once
Take a screenshot or write down the entire message before closing it. Record the game, the anti-cheat name or logo, any number such as 119, the exact filename, and the displayed path.
- Select Start → Power → Restart. A restart reloads Windows and kernel drivers more completely than merely closing the RGB or monitoring app.
- Launch the game from its normal official launcher. Do not use a modified executable or an unofficial anti-cheat bypass.
- If the error disappears, check the utility for an update before assuming the conflict is permanently resolved.
Identify which utility installed your copy
If the error gives C:\Windows\System32\drivers\MsIo64.sys, paste that exact path into File Explorer's address bar. If your message shows another location, use that location instead.
- Right-click the file and select Properties.
- On Details, note the Company name, Product name, File description, and File version.
- If a Digital Signatures tab exists, open it and note the signer. A valid signature helps establish the publisher; it does not guarantee that an old version is compatible.
- Open Settings → Apps → Installed apps and look for the matching motherboard, RGB, fan-control, or monitoring utility.
If Properties still does not identify the owner, download Autoruns from Microsoft Sysinternals, run it as administrator, enable signature verification, open the Drivers tab, and search for MsIo64. Record the entry, publisher, and image path. At this stage, use Autoruns to identify the driver only—do not immediately uncheck or delete the entry.
If the file is missing, do not download a replacement .sys file. The error may be referring to a registered or previously loaded driver. Use the app list and the exact error details to contact the PC or motherboard maker.
Update Windows and the owning utility from official sources
EA's official guidance for blocked software is to update it first. Microsoft gives the same first step when Windows protection blocks an incompatible driver.
- Open Settings → Windows Update, check for updates, install the applicable updates, and restart.
- Find the exact PC or motherboard model. Use only its manufacturer's support page or the utility's built-in updater.
- Install the current supported version of the matching RGB, fan-control, motherboard, or monitoring utility.
- Restart even if the installer does not request it, then test the protected game.
Avoid generic “driver updater” sites and websites offering a standalone MsIo64.sys download. A kernel driver should arrive through the correct signed package for your hardware and Windows version.
Make sure the old version was actually replaced
Return to the file's Properties → Details after the update and compare its version with the one you recorded. Then restart and test again.
- If the version changed but the same block remains, check the game publisher's current support page in case its anti-cheat block has not yet been revised.
- If the version did not change, the updater may not own that copy, or an older utility may be reinstalling it at startup.
- If the file has no valid signature or its claimed publisher does not match any installed product, run an updated Windows Security scan and ask the PC maker or a qualified technician to identify it.
Choose the route that matches the file publisher
Use this table only after the file's Properties or digital signature identifies the owner. The same filename has appeared in software from more than one vendor, so the brand name must come from your own file—not from a search result.
| Confirmed publisher or utility | Preferred route | If a clean reinstall is needed |
|---|---|---|
| MSI Center or Dragon Center | Open the support page for the exact MSI product and install its current supported utility package | MSI documents its official Clean Center Master for removing MSI Center and Dragon Center components before reinstalling; save profiles and expect a restart |
| ASUS Armoury Crate or Aura | Use the exact ASUS product's support page and current Armoury Crate/Aura package | ASUS provides an official Armoury Crate Uninstall Tool; follow the tool's instructions and restart |
| Another signed vendor utility | Use that vendor's support page for the exact motherboard, PC, or device model | Use a cleanup tool only when the confirmed publisher supplies it for that product; otherwise uninstall through Windows Settings |
| Unknown, unsigned, or mismatched publisher | Do not install an MSI or ASUS package by guesswork; scan the file and ask the PC maker or a qualified technician to identify it | Do not use a third-party driver remover or download a replacement .sys file |
Cleanly uninstall the obsolete utility if you do not need it
If no compatible update exists, or the utility is no longer needed, remove the application that installed the driver rather than editing System32 yourself.
- Record any RGB, fan, or performance profile that you may want later.
- Open Settings → Apps → Installed apps.
- Find the confirmed owning utility, select its menu, and choose Uninstall.
- If the manufacturer supplies an official cleanup tool for that exact utility, follow its instructions.
- Restart Windows, then launch the game normally.
Cooling-control exception: If the utility uniquely controls a pump, custom fan curve, or other essential cooling function, do not remove it blindly. Confirm the hardware's safe firmware/default behavior with the PC, motherboard, cooler, or system builder first.
If the driver returns, isolate the service or updater that restores it
A driver that returns after removal normally has another related service, updater, or vendor suite reinstalling it. Recheck Installed apps for a second hardware-control package from the same publisher.
If the owner is still unclear, use Microsoft's documented clean-boot procedure to isolate non-Microsoft services and startup apps. Keep a record of everything you disable and restore normal startup after the test.
- If the game works in the clean-boot environment, re-enable groups of non-Microsoft items until the conflicting utility is identified.
- If the same named-driver error remains in a clean boot, send the saved file and error details to the hardware-utility publisher and the game's support team.
- Do not disable every service permanently; a clean boot is a diagnosis, not the finished configuration.
Repair the correct anti-cheat only after resolving the driver
Reinstalling anti-cheat cannot make an incompatible driver safe. Use this step only when the MsIo64.sys warning is gone but the game now shows an anti-cheat installation or service error.
- Easy Anti-Cheat: verify the game files in the official launcher, then follow the game publisher's EAC installation or repair instructions. Epic's EAC guidance is game-specific.
- EA Javelin anticheat: EA documents its installer under
C:\Program Files\EA\AC\EAAntiCheat.Installer.exe. Select the affected game, uninstall its anti-cheat entry, and reinstall it according to EA's official instructions. - Restart and launch the game through its normal EA, Epic, or Steam entry.
What not to do
- Do not download MsIo64.sys from a driver-download website. You cannot verify that it belongs to your hardware or is safe.
- Do not rename or delete the file in System32 as the first fix. This separates the file from its installer and can leave a broken service behind.
- Do not turn off Secure Boot, Memory Integrity, or the vulnerable-driver blocklist just to launch a game. Microsoft warns that disabling those protections reduces device security.
- Do not add the driver or whole Windows folder to antivirus exclusions. The error is a compatibility/security decision, not evidence that antivirus scanning caused it.
- Do not use a no-anti-cheat launch option for protected online play. If a developer provides an official offline or single-player option, it may be useful for diagnosis, but it does not resolve the blocked driver for multiplayer.
How to confirm the problem is actually fixed
| Check | Fixed result | Unresolved result |
|---|---|---|
| Protected game launch | The game reaches its normal menu with anti-cheat enabled | It works only when anti-cheat is bypassed or disabled |
| Driver warning | The MsIo64.sys message no longer appears after another restart | The same file and version are named again |
| Hardware utility | A compatible version works, or the unwanted utility was cleanly removed | RGB, sensors, fan, or pump behavior is unexpectedly broken |
| Windows protection | Secure Boot, Memory Integrity, and the driver blocklist remain in their prior secure state | A security feature had to be disabled to keep the game running |
Primary references: EA explains that an incompatible-software warning means the named software is blocked for security and should be updated or disabled through its manufacturer. Epic documents the exact “Please unload [driver] before starting the game” pattern, broader Easy Anti-Cheat security violations, and its general EAC game checks. Microsoft recommends an updated compatible driver or removal of its app when a driver cannot load, and explains why the vulnerable-driver blocklist exists. NIST records older affected versions in MSI Dragon Center and ASUS Aura Sync. Guidance was checked July 28, 2026; utility names and menu labels can vary by PC and software version.
Frequently asked questions
Is MsIo64.sys a virus?
Not necessarily. Legitimate hardware utilities have installed files with this name, but the filename alone cannot prove who published your copy or whether its version is safe. Check the file path, Details, and Digital Signatures; update Windows Security and scan the file if its publisher is missing or unexpected.
Should I rename MsIo64.sys to MsIo64.sys.old?
Not as a first or general fix. That can stop a driver from loading but leaves its service and owning utility in an unsupported state. Update or cleanly uninstall the confirmed utility instead. If a manufacturer explicitly provides removal instructions for your exact product, follow those instructions.
Is MsIo64.sys from MSI or ASUS?
It can be associated with more than one vendor utility. Official vulnerability records document older versions in MSI Dragon Center and ASUS Aura Sync. Use your file's signer, product details, version, and installed-app list rather than guessing.
Why did the error appear when the game worked yesterday?
The game, anti-cheat blocklist, Windows protection, or hardware utility may have updated. A newly enforced block can expose an old driver that was already installed. That timing does not mean your hardware suddenly failed.
Can I just launch without Easy Anti-Cheat?
Only use an official offline or single-player option supplied by the game developer, and expect protected multiplayer to be unavailable. A no-anti-cheat launch does not fix the incompatible driver and should not be used to bypass protection in online play.
Does your message name a different driver or error code? Use the exact wording. Related guides: Steam Error Code 54, Fortnite won't launch, and DPC Watchdog Violation.
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