I use the PSWindowsUpdate module, to update via the tool box.
You can use “Install-Module PSWindowsUpdate” to actually install it.
You can use this command to get applicable updates:
Get-WUList -MicrosoftUpdate
You can use this command to apply the updates:
Get-WUInstall -AcceptAll -Install -MicrosoftUpdate -IgnoreReboot
You’ll probably want to schedule a reboot with Task Scheduler.
It works extremely well, there is more information on: http://woshub.com/pswindowsupdate-module/
Alternatively you can use “Get-Command -Module PSWindowsUpdate” within Powershell, then use:
Get-Help <Get-WUInstall, etc.>
It has a suite of functions that help with scheduling as well, also determining if you need to reboot the system with Get-WURebootStatus