This update makes quality improvements to the servicing stack, which is the component that installs Windows updates. Servicing stack updates (SSU) makes sure that you have a robust and reliable servicing stack so that your devices can receive and install Microsoft updates.

If you’re on a Windows 10 device, select Update & Security. If you’re on a Windows 11 device, select Windows Update. Select Check for updates to see if any updates are available for your device. After the updates have downloaded, select Install now to start the installation.

The servicing stack includes the files and resources that are required to service a Windows image. This includes the Package Manager executable, the required servicing libraries, and other resources.

Learn more about update KB4555449, including improvements and fixes, any known issues, and how to get the update.

Addresses an issue in the servicing stack when you install an update that has been signed by using only the SHA-2 hash algorithm. Microsoft strongly recommends you always install the latest servicing stack update (SSU) for your operating system before installing the latest monthly security update.

This update makes quality improvements to the servicing stack, which is the component that installs Windows updates. Servicing stack updates (SSU) makes sure that you have a robust and reliable servicing stack so that your devices can receive and install Microsoft updates.

Learn more about this servicing stack update, including improvements and fixes, any known issues, and how to get the update.

Yes, all versions of Windows and Windows Server might need an SSU to address an issue, including the latest version of Windows 10 and Windows Server.

Describes a servicing stack update for Windows 7 SP1 and Windows Server 2008 R2 SP1.

Learn about this SSU update for Windows 7 SP1 and Server 2008 R2 SP1, including improvements and fixes, any known issues, and how to get the update.