March’s optional Windows 11 update arrives with a key security feature


Summary created by Smart Answers AI
In summary:
- PCWorld reports on Microsoft’s optional Windows 11 update KB5079391, which introduces Smart App Control flexibility and support for ultra-high 1,000Hz refresh rate displays.
- The update matters for gamers seeking future-proof display compatibility and users wanting better control over security features without system reinstallation.
- Key improvements include reduced USB4 power consumption, enhanced HDR reliability, File Explorer voice control upgrades, and new Microsoft 365 settings integration.
Microsoft has begun rolling out KB5079391. This optional update adds a number of small but useful new features to Windows 11.
Among other things, it allows Smart App Control (SAC) to be activated or deactivated without having to reinstall the operating system, a feature that, to say the least, has long been anticipated.
SAC is a security feature that prevents malicious apps from running on your PC. It usually works reliably, but sometimes SAC overreacts and classifies perfectly normal apps as malicious, preventing you from running them without authorization.
By the way: If you’re using Windows 11 Home, you’re missing out on the many benefits of Windows 11 Pro. To learn more, see our comparison of Windows 11 Home and Pro. If you want to upgrade, snag it for cheap in the PCWorld Software Store: now just $59 instead of $99.
What else is new in KB5079391?
We’re getting support for displays with up to 1,000Hz refresh rates, making the operating system somewhat more future-proof against high-end monitors with crazy speeds for gamers. The first monitor to ever break this record was shown at CES 2026 earlier this year.
Additionally, power consumption when using a USB4 port will be reduced, and the reliability of HDR is expected to be much better.
Windows Latest also reports that various improvements to File Explorer and new settings for Microsoft 365 are being rolled out. These include enhanced voice control, and you can also sort permissions via the “Advanced Security Settings” pop-up window in File Explorer.
How to get the update
As usual, the easiest way to install KB5079391 is to open Windows Update, check for the update, and then follow the installation instructions. Alternatively, you can install it directly via the Microsoft Update Catalog.
Currently, there are no known problems with the update. However, as we all know, that can change quickly with Windows 11…
This article originally appeared on our sister publication PC för Alla and was translated and localized from Swedish.
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