Now no matter installing Microsoft's Windows operating system or Office software for computer, that can be done directly through Windows Update function. But it's a weakness: always needs Internet connection, and has to redownload all files every time you want to install an update. Therefore, if we can download the offline update files and store them on local drive, then we will be able to use these Windows Update files anytime and anywhere. This is pretty good for system maintainers and IT administrators of companies at least.