In search of this same solution, I found what I needed under a different question in stackoverflow: Powershell-log-off-remote-session. The below one line will return a list of logged on users.

query user /server:$SERVER

Molan, can you post what you are using?

I posted it in the SW Script center

https://community.spiceworks.com/scripts/show/4755-remote-trouble-shooting-and-information-gathering-script

@ericjennings2

The environment variable [System.Environment]::GetEnvironmentVariable('username') will give you the username for the executor of the script, in your case that is System because this is user who ran the code.

If you want to user the environment variable for the user, you must make it so the script been ran from or on behalf of the user, this also means that user must have "permissions" to modify the registry.

If I understand right, you need to know who is the "Logged in user" for the machine where that script runs, unfortunately there is nothing available from PowerShell that do that to my knowledge, instead you could use the build-in tool query for Windows machines, which will provide you with a list with all logged in users to that machine, you would need to further test it to get what you want from it, the output looks like this :

PS C:\Users\t-user> query user
 USERNAME              SESSIONNAME        ID  STATE   IDLE TIME  LOGON TIME
>t-user                console             1  Active      none   8/29/2022 11:58 AM

The trick with query user is that it will provide you with the list of users in case more than one have logged in.

I see what you are trying to do, and here is a "dirty" example of doing it :

$loggedUserList= query user

if($loggedUserList.count -eq 2){
    $user = $loggedUserList -split ">" -replace '\s\s+', ';' | convertfrom-csv -Delimiter ';' | select -ExpandProperty username
    Write-Host "Logged in user is - $user"
}else{
    Write-Host "More than one user have signed"
}

The issue with Get-WmiObject Win32_LoggedOnUser | Select Antecedent -Unique is that it shows all sessions even those that have been closed since the last time the computer rebooted. The easiest way to poll sessions is unfortunately using the old executable query.exe.

You can convert the output of query.exe to objects using a bit of regex:

$Computer = $env:COMPUTERNAME
$Users = query user /server:$Computer 2>&1

$Users = $Users | ForEach-Object {
    (($_.trim() -replace ">" -replace "(?m)^([A-Za-z0-9]{3,})\s+(\d{1,2}\s+\w+)", '$1  none  $2' -replace "\s{2,}", "," -replace "none", $null))
} | ConvertFrom-Csv

foreach ($User in $Users)
{
    [PSCustomObject]@{
        ComputerName = $Computer
        Username = $User.USERNAME
        SessionState = $User.STATE.Replace("Disc", "Disconnected")
        SessionType = $($User.SESSIONNAME -Replace '#', '' -Replace "[0-9]+", "")
    } 
}

Which will give you output like this:

ComputerName Username SessionState SessionType
------------ -------- ------------ -----------
BSMITH-LT    bobsm    Active       console    

Taking it a lot further in to a function:

function Convert-QueryToObjects
{
    [CmdletBinding()]
    [Alias('QueryToObject')]
    [OutputType([PSCustomObject])]
    param
    (
        [Parameter(Mandatory = $false,
                   ValueFromPipeline = $true,
                   ValueFromPipelineByPropertyName = $true,
                   Position = 0)]
        [Alias('ComputerName', 'Computer')]
        [string]
        $Name = $env:COMPUTERNAME
    )

    Process
    {
        Write-Verbose "Running query.exe against $Name."
        $Users = query user /server:$Name 2>&1

        if ($Users -like "*No User exists*")
        {
            # Handle no user's found returned from query.
            # Returned: 'No User exists for *'
            Write-Error "There were no users found on $Name : $Users"
            Write-Verbose "There were no users found on $Name."
        }
        elseif ($Users -like "*Error*")
        {
            # Handle errored returned by query.
            # Returned: 'Error ...<message>...'
            Write-Error "There was an error running query against $Name : $Users"
            Write-Verbose "There was an error running query against $Name."
        }
        elseif ($Users -eq $null -and $ErrorActionPreference -eq 'SilentlyContinue')
        {
            # Handdle null output called by -ErrorAction.
            Write-Verbose "Error action has supressed output from query.exe. Results were null."
        }
        else
        {
            Write-Verbose "Users found on $Name. Converting output from text."

            # Conversion logic. Handles the fact that the sessionname column may be populated or not.
            $Users = $Users | ForEach-Object {
                (($_.trim() -replace ">" -replace "(?m)^([A-Za-z0-9]{3,})\s+(\d{1,2}\s+\w+)", '$1  none  $2' -replace "\s{2,}", "," -replace "none", $null))
            } | ConvertFrom-Csv

            Write-Verbose "Generating output for $($Users.Count) users connected to $Name."

            # Output objects.
            foreach ($User in $Users)
            {
                Write-Verbose $User
                if ($VerbosePreference -eq 'Continue')
                {
                    # Add '| Out-Host' if -Verbose is tripped.
                    [PSCustomObject]@{
                        ComputerName = $Name
                        Username = $User.USERNAME
                        SessionState = $User.STATE.Replace("Disc", "Disconnected")
                        SessionType = $($User.SESSIONNAME -Replace '#', '' -Replace "[0-9]+", "")
                    } | Out-Host
                }
                else
                {
                    # Standard output.
                    [PSCustomObject]@{
                        ComputerName = $Name
                        Username = $User.USERNAME
                        SessionState = $User.STATE.Replace("Disc", "Disconnected")
                        SessionType = $($User.SESSIONNAME -Replace '#', '' -Replace "[0-9]+", "")
                    }
                }
            }
        }
    }
}

and now you can do things like: Get-ADComputer -Filter {Name -like "SERVER*"} | Convert-QueryToObjects | ? {$_.SessionState -eq 'Active'}

We have a remote pc which is fairly unstable. (separate issue we’re working on it)

How can I remotely test IF that remote pc is logged IN. (not just ON but actually logged in)

The problem of course is if the pc is not logged in the reports do not run. I can test if it’s up through a variety of mechanisms (ping, test for admin share etc). IS there a way I can programmatically test if the pc is actually logged IN.

Windows 10 in an AD hybrid environment.

Try this

$MachineList = Get-Content -Path c:\ListOfMachines.txt; # One system name per line
foreach ($Machine in $MachineList){
    ($Machine + ": " + @(Get-WmiObject -ComputerName $Machine -Namespace root\cimv2 -Class Win32_ComputerSystem)[0].UserName);
}