Why you should install this update
We strongly recommend that you install Windows 8.1 Update or Windows RT 8.1 Update (KB 2919355). This is a critical update that is required for future updates to Windows. If you prevent it from installing or you uninstall it, you won’t get future bug fixes, security updates, and new features. In some cases, if you uninstall this update from a new PC after signing in with a Microsoft account, OneDrive might not work as expected.