Servicing stack updates provide fixes to the servicing stack, the component that installs Windows updates. Additionally, it contains the “component-based servicing stack” (CBS). The Component-Based Servicing (CBS) is crucial in Windows deployment. It’s integral to DISM, SFC, changing Windows features or roles, and component repairs. The CBS is a small component that typically does not have updates released every month. You can search to install the latest available Servicing stack update for Windows 10. Here are some related contents. How to automate Windows Update with PowerShell and Task Scheduler, Windows as a Service: Windows 10 Feature and Quality Updates, how to enable or disable automatic software updates on Mac, how to set up and configure Windows server update services (WSUS), and how to configure SSL between WSUS upstream and downstream servers.

Receiving New Cumulative updates

Microsoft announced on 09.02.2021 that they have released servicing stack update (SSU) for Windows 10 and this applies to the various Windows version (1909, 1809, 1607, and 1507). Starting from February 2021, these SSU will be a prerequisite for receiving the new cumulative update (LCU and SSU packaged together) for these versions of Windows 10 (1909, 1809, 1607, and 1507).

Microsoft is currently considering transitioning to the new combined package format. This transitioning will happen for earlier versions (e.g., 2004, 20H1, 20H2, etc.) in the upcoming months. They recommend deploying the February 2021 SSU organization-wide to prepare for this change. This provides ample time for deploying the September 2020 SSU and LCU broadly across your organization.

IT administrators need to carefully choose and deploy the appropriate servicing stack update (SSU) along with the latest cumulative update (LCU) to maintain device currency. Especialy when managing devices through on-premises methods. In some cases, a specific version of the SSU must already be installed in order to install the latest LCU. If the device in question does not have the required SSU already installed, the LCU will fail to install.

If you do not have the SSU installed and the LCU fails, this can be a daunting task to handle. From Microsoft documenatation, the following errors are possible.
- First, it doesn't occur every month.
- The error message that the LCU failure can produce, "update isn't applicable," doesn't make the root cause immediately apparent.

Therefore, having an LCU failure to install error can be confusing and frustrating for both end-users and IT admin. It can also hurt security compliance. In the Windows Update process, the device receives both the SSU and LCU simultaneously. The update stack manages their installation, ensuring correctness.

Why was the Servicing Stack Update introduced?

The SSU ensures that Windows Administrator can effortlessly manage cloud and on-premise devices. Achieving this involves bundling a single cumulative monthly update with fixes for the month. If needed, it also includes the necessary servicing stack updates. They also stated that the upcoming changes will ensure that the SSU and LCU are provided together under a single payload to both Windows Server Update Services (WSUS) and Microsoft Catalog.

Servicing stack updates improve the reliability of the update process to mitigate potential issues while installing the latest quality updates and feature updates. If you don't install the latest servicing stack update, there's a risk that your device can't be updated with the latest Microsoft security fixes.

If you use WSUS and the Configuration Manager in your environment, you will select and deploy the monthly cumulative update. The most recent SSU will be automatically applied correctly. Since the introduction of SSU, the following will no longer be relevant to IT Administrators.

Searching for both the SSU and LCU KB articles. All release notes and file information for monthly cumulative updates, including those related to the servicing stack, will be in a single KB article!
Determining if this month’s LCU has a dependency on a specific SSU version or newer and ensuring that the right SSU and LCU are deployed and installed in the correct order. The client will package the SSU and LCU together and orchestrate their installation. Select the monthly cumulative update you want to deploy, and we will take care of the rest!
End users confused at seeing multiple servicing releases in a month. The Window Update Settings and History pages will now look the same as it does for those who update from the cloud today!

To proceed with the rollout of the SSU, and to start to receive a single monthly cumulative update package containing the SSU and LCU, you will first need to broadly deploy the September 2020 SSU or any later SSU on all Windows 10, version 2004 devices in your organization.

When are they released?

Servicing stack updates are released based on the presence of new issues or vulnerabilities. On rare occasions will a servicing stack update be released on demand to address an issue impacting systems installing the monthly security update. Starting in November 2018 new servicing stack updates will be classified as “Security” with a severity rating of “Critical.”

I hope you found this blog post helpful. If you have any questions, please let me know in the comment session.