Updating Windows systems is one of the routine tasks of an administrator, usually done automatically with or without WSUS. The problem with it is, as we all know, that users are bothered by the time-consuming process of requesting available updates and reboots - not only at Microsoft Patch Day. That is where WuInstall comes in because with WuInstall the administrator (or the user) can decide when he wants to look for updates and if he wants to download and install them.
WuInstall is a command line tool for Windows which enables you to install Windows updates for a certain workstation in a controlled way, by using a command line script instead of the standard Windows update functionality.
It allows administrators to update several workstations at once (e.g. run WuInstall in shutdown scripts) or workstations of users who turned off Windows Automatic Updates.
WuInstall is written in C++. It is roughly comparable with the apt-get update/upgrade command in Linux, which does not exists for Windows.
WuInstall uses the Windows update API and searches, either at the internal WSUS server or on the external Microsoft Update Server (depending on system configuration), for currently available updates for the certain workstation. The tool downloads and/or installs the found updates. The administrator chooses the appropriate time for searching and for installing updates. All actions can be separated: you have the option to only see which updates are available right now, or to download them without installing right away, or to install them.