The August monthly security update is causing many problems in Windows 11. Either the update fails to install or it causes performance issues on PCs.

There are few certainties in life, but the fact that a Windows update causes problems can be devastating. Update KB5041585 seems to make a big difference. Many Windows users are unable to get the update installed on their device. If you do manage to do so, your PC will not function properly after installation.

KB5041585 is the latest monthly security update for Windows 11. Microsoft asks that you install the update as soon as possible. The update fixes a potentially extremely dangerous security vulnerability that allows attackers to exploit IPv6 to execute malicious code on your device.

However, for many Windows users, the installation is not so smooth that they cannot install the update at all. If the update does not run automatically via the update menu in the settings, you can download KB5041585 manually via the Microsoft Update Catalog.

CPU at full speed

It’s also causing problems for those who have installed the update. On Reddit, users are reporting that the update “completely ruined their laptop.” The update appears to be causing CPU overload on many Windows PCs, resulting in noticeable slowdowns and even complete system crashes.

If this is the case, there is no other option for now than to undo the installation. Read our instructions on how to uninstall a faulty Windows update. It is recommended that you temporarily disable IPv6 in Windows. You can do this with the following command in PowerShell:

Set-ItemProperty -Path HKLM:\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters -Name “DisabledComponents” -Value 0xFF -Type DWord

The update also fixes a bug in Secure Boot. This patch has catastrophic side effects for Linux dual boot. It is far from the first and most likely not the last Windows update to cause problems, but KB5041585 already has a lot to offer.