September cumulative updates have become a real headache for Windows users.
After the release of the next updates for Windows on Tuesday, September 11, users have traditionally encountered a number of problems. One of them is an incomprehensible error message that appeared after turning on the computer (laptop, smartphone or tablet): “Error. The SSU could not be installed before the LCU. Turn off your computer and turn it on again. ” What are the SSU and LCU, and why they could not be installed, it is understandable not all Windows users.
SSU is a Servicing Stack Update, that is, a service stack update. The service stack is the code for installing other OS updates. Additionally, it contains the Component-based servicing (CBS) service, which is a key component for multiple Windows deployment elements. CBS is a small component, usually not getting updates every month.
Updates to the maintenance stack are released from time to time. For example, September 11, was released update KB 4456655 for Windows 10 build 1803.
LCU is an abbreviation of Latest Cumulative Update (the latest cumulative update). The main rule is that the update of the service stack should be installed before the last cumulative update. However, the Windows Installer does not follow this rule for some unknown reason, and as a result, users encounter an error when turning on their devices.
Violation of the rule “SSU before LCU” is also the cause of the second problem that occurred with the installation of the September cumulative update for Windows 7. When you try to install KB4457144, an error 0X8000FFFF occurs. As it turned out, you first need to manually install the update of the maintenance stack KB3177467 two years ago and only then install KB4457144. You do not need to reboot the system after installing KB3177467.