What can I query to see if Windows is booted and done with updates?

Question

My goal is to remotely check a group of computers (extensive list) not only to see if the server has rebooted (usually when it was last rebooting), but if Windows is fully up and running at the login screen, and it won't restart for further updates or still be installing updates.

I did find a service called AppReadiness, which stopped it until the server rebooted. I am concerned that if it is set to manual, it may not always start. Could somebody please confirm if this is a reliable service?

EDIT: As I'm writing this, I did find out that it was stopped until it says "Working on updates, 100% complete, Don't turn off your computer" but as the server hung on that message, the AppReadiness service started. Is there anything better to watch? I've read other answers on different questions say to check if C$ is available, but that is available sooner than AppReadiness is available.

The code that is being used to check the service:

$creds = Get-Credential -Message "Enter server credentials:" -UserName "SERVERNAME\Administrator"
Get-WmiObject Win32_Service -ComputerName "SERVERIPADDRESS" -Credential $creds | Where-Object {$_.Name -eq "AppReadiness"}

EDIT 2: Also, instead of monitoring services, I have also tried looking for processes like winlogon.exe and loginui.exe for guidance on the server's condition but I'm not receiving the results I'm looking to record. These processes show when the server is getting ready when I was hoping they would only show once the login GUI was visible.

EDIT 3:

This edit is for the answer by @Kelv.Gonzales who stated to check for the Windows Event Log "DHCPv4 client service is started" log entry. That doesn't work and is on par with other services and events that I monitored. It shows valid before the login screen.

My code was:

$creds = Get-Credential -Message "Enter server credentials:" -UserName "SERVERNAME\Administrator"
$server = "IPADDRESSOFSERVER"

while($true)
{
    $event = Get-WmiObject Win32_NTLogEvent -ComputerName $server -Credential $creds -Filter "(logfile='System' AND eventcode = '50036')" | select -First 1
    $event.ConvertToDateTime($event.TimeWritten)
    Start-Sleep -Seconds 5
}

Answer 1

That one liner will just fire off once of course. Any reason why you are using WMI, instead of the built-in PowerShell cmdlet - Get-Service?

My suggestion is use an WMI Event watcher, using what you already have in place but target the service and any dependent services and have that event notify you when the state is running.

Use PowerShell to Monitor and Respond to Events on Your Server

This article is using PowerShell and VBScript to do this, but you can do this with all PowerShell.

You can have a temporary or permanent watcher.

PowerShell and Events: WMI Temporary Event Subscriptions

Those can get a bit deep, so, if they aren't for you, you can just use your one line in a Do Loop that stops after the service comes online.

Basic example:

$TargetHost = $env:COMPUTERNAME
do {
    $TargetOperation = Get-WmiObject Win32_Service -ComputerName $TargetHost  | 
    Where-Object {$_.Name -eq "AppReadiness"}
    "Checking host $TargetHost for service/process $($TargetOperation.Name)"
    Start-Sleep -Seconds 3
} until (($TargetOperation).State -eq 'Running')
"Validation of host $TargetHost for service/process $($TargetOperation.Name) complete"

# Results

Checking host WS70 for service/process AppReadiness
Checking host WS70 for service/process AppReadiness
Checking host WS70 for service/process AppReadiness
Validation of host WS70 for service/process AppReadiness complete

You can of course add as many services or processes as you'd like using operation logic.

All the above applies to almost whatever you'd like to watch. Services, process, file-folder.

Or just use this script in the loop.

Get Remote Logon Status - Powershell

This script will return the logon status of the local or a remote machine. Return types include "Not logged on", "Locked", "Logged on", and "Offline.

The most useful part of this is to check whether a computer is in the locked state, although the other return types could also be useful.

This is a simple function, and can easily be included in a larger script. The return types could be changed to numbers for the calling script to more easily parse the return value.

Download: GetRemoteLogonStatus.ps1

Answer 2

Would finding 0 updates queued accomplish what you need then? This arcticle goes into detail on how to accomplish it.

To check if windows is ready to log in, can you query for the event log for 'DHCPv4 client service is started' - Event ID 50036 satisfy if windows is ready.