UsoClient.exe replaces wuaulctl
RefreshSettings – used to quickly enact any settings changes
RestartDevice – as the name implies, it restarts the device. Can be used in a script to allow updates to finish installing on next boot.
ResumeUpdate – used to tell the tool to resume updating after a reboot.
StartDownload – initiates a full download (from Microsoft) of existing updates
StartInstall – kicks-off the installation of the downloaded updates
ScanInstallWait – Combined Scan Download Install
StartInteractiveScan – we’ve yet to get this one to work, but it suggests that the process may work in a GUI
StartScan – kicks-off a regular scan