Package KBxxxxxxx failed to be changed to the Installed state. Status: 0x800f0821
When you install Windows Update from SCCM – Software Center, the installation fails. If you retry the operation, the installation fails again. Re-installing SCCM client or restarting Windows machine will not fix the issue.
On the Windows machine browse C:\Windows\SoftwareDistribution\Download you will find a folder name with some alphanumeric characters. Open the folder and you will get a .cab file for the failed update. Copy the .cab file to C:\ and run following command from an elevated command window.
DISM.exe /Online /Add-Package /PackagePath:c:\kbxxxxxxx.cab
The package installation will take longer than normal installation however you can see the progress bar in the command window. You might need to press Enter key when you see 100% completion to check if the restart is required to complete package installation.