KB5025221: Windows Update SSU

Improvements

• This update addresses security issues for your Windows operating system.

Bug fixes

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

Open issues

• Devices with Windows installations created from custom offline media or custom ISO image might have Microsoft Edge Legacy removed by this update, but not automatically replaced by the new Microsoft Edge. This issue is only encountered when custom offline media or ISO images are created by slipstreaming this update into the image without having first installed the standalone servicing stack update (SSU) released March 29, 2021 or later.

Workaround

• To avoid this issue, be sure to first slipstream the SSU released March 29, 2021 or later into the custom offline media or ISO image before slipstreaming the LCU. To do this with the combined SSU and LCU packages now used for Windows 10, version 20H2 and Windows 10, version 2004, you will need to extract the SSU from the combined package. Use the following steps to extract the SSU:

1. Extract the cab from the msu via this command line (using the package for KB5000842 as an example): expand Windows10.0-KB5000842-x64.msu /f:Windows10.0-KB5000842-x64.cab <destination path="">
2. Extract the SSU from the previously extracted cab via this command line: expand Windows10.0-KB5000842-x64.cab /f:* <destination path="">
3. You will then have the SSU cab, in this example named SSU-19041.903-x64.cab. Slipstream this file into your offline image first, then the LCU.</destination></destination>