Last Updated on May 4, 2026
Windows 11 is more secure than Windows 10 was, which is a good thing for the most part. But with more security comes more potential for those security features to prevent you from getting your work done when they block things you do not want to be blocked.
Windows has a built-in security tool called Smart App Control (SAC) which is part of the Windows Security Center. The SAC tool was designed to prevent you from opening files and apps that might not be safe to open on your computer. As you probably know, when you download files from the internet you do not always know what you are getting and might end up with a virus or malware or maybe something worse.
If you try to open a file that SAC thinks is unsafe, you will receive a message that says, “Smart App Control blocked a file that may be unsafe” and not allow you to open it. Then you will only have the option to click OK, send feedback or look for another app in the Microsoft Store.
Unblocking a single file
If you would rather not mess with the Smart App Control settings and simply unblock a single file, you can do this with just a few steps.
To unlock the file, you will need to right click on it and choose Properties. You should then see an Unblock checkbox within the General tab. You can then check this box and click OK.
You should then be able to open your file without any restrictions. One thing you will notice is once you check the Unblock checkbox, it will no longer be there the next time you check the file properties.
If you want to add the Unblock checkbox back to the file properties, you can run the following PowerShell command to do so. Just be sure to edit the file path and file name to match your environment.
Set-Content -Path “C:\Your\File\Path\Here.iso” -Stream Zone.Identifier -Value “[ZoneTransfer]`nZoneId=3”
Disabling and Enabling Smart App Control
If you don’t want SAC to be controlling what files you are allowed to open or what apps you are allowed to use, you can disable it, assuming it is turned on.
If you go to the Windows Security Center or just type Smart App Control in the taskbar search box, you will be able to see whether or not SAC is enabled. The Evaluation option will most likely be greyed out unless you are running a recently installed version of Windows.
The Evaluation process is used to monitor how you use your computer after installing Windows. Then it will determine whether or not to enable Smart App Control based on the types of files you are opening and the apps you are running. In earlier builds of Windows, you were not able to change this setting once SAC chose the option for you.
One thing to be aware of is if you turn Smart App Control off and try to open a blocked file, you will not get a warning from SAC and will most likely just not be able to open the file. If this happens, you can then go back to the properties for that file and see if you have the Unlock option.
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