Servicing Stack Updates (SSU): Frequently Asked Questions

Servicing stack updates provide fixes to the servicing stack, the component that installs Windows updates. For more background information on SSUs, please see this article. 

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.

SSUs should always be installed before any new update for Windows, including the latest cumulative update (LCU), Monthly Rollup, or Security-only update.

The latest SSU for your device can be found in ADV990001 | Latest Servicing Stack Updates.

All updates for Windows 7 SP1, Windows Server 2008 R2 SP1, and Windows Server 2008 SP2 released after August 13, 2019 are SHA-2 signed, including SSUs. For general information, installation and troubleshooting related to the change to SHA-2 signed updates, please see 2019 SHA-2 Code Signing Support requirement for Windows and WSUS.

Before you restart your device, install the latest Servicing Stack Update (SSU) as listed in ADV990001 | Latest Servicing Stack Updates. Once the SSU has installed successfully, you can restart your device.

The steps below will resolve the issue, if it is caused by missing the installation of an SSU.

Using Safe Mode:

1. To enter Safe Mode, tap the F8 as soon as you see that Windows is starting.

2. Select Safe mode from the menu and wait for Windows to start up.

3. Restart your device.

4. Windows should now start normally.

5. Install the latest Servicing Stack Update (SSU) as listed in ADV990001 | Latest Servicing Stack Updates.

6. You should now be able to install the other update to Windows.

Or using Windows Recovery Environment (WinRE):

1. To enter the Windows Recovery Environment, see Entry points into WinRE.

2. In WinRE, you will need to click troubleshooting or advanced and then open a command prompt.

3. Run the following command (assuming windows is installed on C:\): DISM /image:C:\ /cleanup-image /revertpendingactions

4. Restart the device and wait for Windows to start.

5. Install the latest Servicing Stack Update (SSU) as listed in ADV990001 | Latest Servicing Stack Updates.

6. You should now be able to install the other update to Windows.