If you check your Windows Update notifications today, you may see that Windows 8.1 will offer you the Windows 8.1 Update KB2919355 package, even if you had installed it earlier. Why is this happening?
Windows 8.1 Update KB2919355 package
Today Microsoft updated its Knowledge Base article to explain this.
Windows Update may offer update 2919355 again even when the computer already has update 2919355 installed. This is expected and is in order to resolve a Windows Update client issue.
If you are using a MSDN and VLSC updated ISO, then too you may be offered this Update again as they do not contain the complete set of fixes that are offered from Windows Update. This will not result in the full reinstallation of the Windows 8.1 Update but only a smal component of it. The rest of the update will not be downloaded or reinstalled.
So if you are seeing this update being offered, go ahead and install KB2919355 again.
Windows Update will install only the additional fixes for Windows Update clients instead of installing the entire Windows 8.1 update packages.
Once you install this new KB2919355 package on your Windows RT 8.1, Windows 8.1, or Windows Server 2012 R2, you will receive all future security and nonsecurity updates. Once it is successfully installed, you will be to se a single KB2919355 entry in the Control Panel. You can use the DISM command to verify the installation or uninstallation of the update. You will be required to restart your Windows 8.1 computer after you have installed this update.
Windows 8.1 Update package KB2919355 introduces several new features. But Windows 8.1 Update has not been installing for many users, in spite of following some troubleshooting steps. Microsoft has urged all to install this update by May 13th.
We hope that this new update published yesterday, which includes some changes to the Windows Update client, goes though smoothly for your Windows 8 computer, and you are able to receive all future Windows Updates.