Please unload MsIo64.sys before starting the game? Try 8 safe fixes
✓ Researched & published July 19, 2026The message means the game does not want to start while a particular Windows driver is loaded. It is commonly shown before an anti-cheat-protected game opens. The safest fix is to identify the program that installed MsIo64.sys, update that program or remove the optional component that uses it, restart Windows, and test again.
The filename normally uses a capital I in MsIo64.sys. It is often mistyped as mslo64.sys with a lowercase L. Match every character in your own error before following this guide; a different .sys filename can belong to different software and needs a different fix.
Do not delete or rename the file in System32 as a first fix. Also do not disable Memory integrity, the Microsoft vulnerable-driver blocklist, antivirus or anti-cheat. A driver can support RGB lighting, sensors, fan control or another hardware utility; removing the wrong package can break that feature. Update or uninstall the owning software through its supported method.
Quick checklist
- Confirm that the message names exactly MsIo64.sys
- Restart Windows and test before opening hardware utilities
- Identify the file publisher and owning application
- Install Windows and PC/vendor utility updates
- Update or remove the related MSI Center feature
- Uninstall the confirmed legacy utility if it is not needed
- Use a clean boot to identify a different loader
- Repair the game/anti-cheat or escalate with evidence
What is MsIo64.sys?
MsIo64.sys has been reported in Microsoft support material as an MSI monitoring/control driver, and older copies may arrive with motherboard, RGB-lighting or hardware-monitoring software. MSI documents that MSI Center can install, update and uninstall feature sets such as Mystic Light and hardware monitoring. However, the filename alone is not enough to prove who installed the copy on your PC. Check its path, Details tab and Digital Signatures before removing anything.
This launch message is not, by itself, proof of malware. It is a compatibility or security decision: the game is refusing to continue while the named kernel driver is active. That is why updating or cleanly removing the driver-owning utility is safer than trying to hide the file from the game.
Match your result before choosing a fix
| What you find | Best next action | What it suggests |
|---|---|---|
| The game opens immediately after a full restart | Open startup utilities one at a time | One background utility loads the driver later |
| The error returns when MSI Center, Mystic Light or another monitor opens | Update or remove that confirmed feature | The utility is the likely driver owner |
| File Properties shows an MSI/MICSYS-related publisher | Use the correct MSI or PC product support page | An MSI-family control utility is the likely branch |
| Properties shows a different publisher or path | Stop using MSI-specific steps and contact that vendor | The similar filename belongs to another package |
| Windows Security also lists the driver as incompatible | Update or uninstall its owning software | The installed driver is old or incompatible with current protection |
The 8 fixes, from lowest to highest impact
Copy the exact message and restart Windows
Take a screenshot that includes the game name and the complete driver filename. Close the launcher, choose Start → Power → Restart, then open only the game launcher and test once. Use Restart rather than Shut down so Windows performs a complete restart cycle.
Verify the filename, path and publisher
Do not act on a forum post until you confirm the local file. If the error provides a path, open that folder carefully; otherwise search Windows for the exact filename.
- Right-click the file and select Properties.
- Record Location, Details, file version and company name.
- Open Digital Signatures when present and record the signer.
- If the file is in Downloads, Temp or an unexpected user folder, do not run or move it; scan the PC with Windows Security.
Check which installed utility owns it
Open Settings → Apps → Installed apps and look for software supplied with the motherboard, prebuilt PC, RGB lighting, overclocking, fan control or hardware monitoring. Common MSI-family names can include MSI Center, Dragon Center or Mystic Light, but your file evidence must point to that branch first.
Also open Windows Security → Device security → Core isolation details. If Windows offers Review incompatible drivers, compare its publisher and published package name with your notes. Do not turn protection off to make the warning disappear.
Install supported Windows and vendor updates
Open Settings → Windows Update, install available updates and restart. Then visit the support page for the exact motherboard, laptop or prebuilt-PC model. Install only the current supported version of the confirmed control utility or driver.
If the owner is MSI Center, use its Live Update and Feature Sets pages. MSI documents these as the supported places to update drivers/utilities and manage optional MSI features.
Update or remove the confirmed MSI Center feature
Use this step only when your file details point to MSI software. In MSI Center, open Feature Sets. Update the installed hardware-monitoring or Mystic Light feature first. If it is optional for your setup and the newest version still loads the blocked driver, use the feature's own Uninstall option, then restart.
- Write down custom lighting, performance and fan settings first.
- Do not remove a cooling or fan-control component unless you understand what will replace its control.
- For an MSI laptop or prebuilt PC, prefer the model-specific MSI support instructions.
Uninstall the confirmed legacy utility cleanly
If the driver belongs to an old utility you no longer need, remove the application through Settings → Apps → Installed apps, not by deleting its .sys file. Restart and test the game. Microsoft recommends uninstalling the associated program first when it appears in the Apps list.
Use a Microsoft clean boot if the owner is still unclear
A clean boot can show whether another non-Microsoft startup service loads the driver. Follow Microsoft's clean-boot instructions, hide Microsoft services before disabling the remaining test items, restart, and test the game once.
- If the error disappears, re-enable the test items in groups until the responsible utility is identified.
- Return Windows to normal startup when the test is complete.
- Do not leave security, cooling or required workplace software disabled.
Repair the game path, then escalate before manual driver removal
After the owning utility is updated or removed and Windows has restarted, verify the game files and repair its anti-cheat component using the official launcher or publisher instructions. Do not download an anti-cheat installer or replacement driver from a third-party site.
If the exact same message remains, collect the screenshot, game name, file path, publisher, file version, Windows version and the utility you updated or removed. Send that evidence to the PC/driver vendor and the game's support team.
Manual driver-package removal is a last-resort administrator task. Microsoft warns that removing the wrong package can leave a device without a working driver and recommends creating a restore point first. Follow model-specific vendor guidance or have a qualified technician identify the exact published driver package; do not guess from the filename.
Primary references: Microsoft's vulnerable-driver blocklist explanation, Microsoft Learn's driver and package removal cautions, a Microsoft support discussion that identifies MsIo64.sys in an MSI/lighting-utility case, MSI's MSI Center feature and update guide, and Microsoft's clean-boot procedure. Checked July 19, 2026.
Frequently asked questions
Is MsIo64.sys a virus?
Not necessarily. It has been associated with legitimate hardware-monitoring and RGB-control utilities. The launch warning means the game objects to the loaded driver; it does not prove malware. Verify the local path, publisher and digital signature, and run Windows Security if anything looks unexpected.
Is the filename MsIo64.sys or mslo64.sys?
The commonly reported driver name is MsIo64.sys, using a capital I after “Ms.” Search text and some fonts make it look like a lowercase L, which produces the query “mslo64.sys.” Always copy the exact filename from your own message.
Can I just rename or delete MsIo64.sys?
That is not the recommended first fix. A registered driver may still have a service or package entry, and the associated hardware feature can stop working. Update or uninstall the confirmed owning utility through Windows or the vendor's tool.
Why does the error appear in more than one game?
Different games can use launch protection or anti-cheat systems that reject the same active kernel driver. Fixing the confirmed driver-owning utility can therefore resolve the message across multiple games.
What if my PC has no MSI hardware?
Do not assume the MSI branch is correct. The driver may have arrived with an older accessory, partner utility or previous hardware installation. Use File Properties and Installed apps to identify the actual publisher, then contact that vendor.
If this message appears while opening Fortnite, continue with our Fortnite launch guide after the driver conflict is cleared. For a different anti-cheat or VAN message, use the VALORANT and Vanguard guide.
Send us the exact details →