How to retrieve the logged on user of a remote machine in powershell

Note: For windows 7 desktop users you’ll need to install the active directory modules for powershell by following the installation steps here
https://www.microsoft.com/en-gb/download/details.aspx?id=7887

A better version could be to filter the process for explorer.exe

Get-WmiObject -class win32_process -Filter "name = 'Explorer.exe'" -ComputerName MACHINENAME -EA "Stop" | % {$_.GetOwner().User}

Or if you wish to resolve down to the actual full person's name

Get-WmiObject -class win32_process -Filter "name = 'Explorer.exe'" -ComputerName WDUKLON-0102 -EA "Stop" | % {Get-AdUser -Identity $_.GetOwner().User | Select -Property Name}

For all logged on users though, use the following script…

 https://gallery.technet.microsoft.com/scriptcenter/d46b1f3b-36a4-4a56-951b-e37815a2df0c
function Get-LoggedOnUser {
#Requires -Version 2.0           
[CmdletBinding()]           
Param            
   (                      
    [Parameter(Mandatory=$true,
               Position=0,                         
               ValueFromPipeline=$true,           
               ValueFromPipelineByPropertyName=$true)]           
    [String[]]$ComputerName
   )#End Param
Begin           
{           
Write-Host "`n Checking Users . . . "
$i = 0           
}#Begin         
Process           
{
    $ComputerName | Foreach-object {
    $Computer = $_
    try
        {
            $processinfo = @(Get-WmiObject -class win32_process -ComputerName $Computer -EA "Stop")
                if ($processinfo)
                {   
                    $processinfo | Foreach-Object {$_.GetOwner().User} |
                    Where-Object {$_ -ne "NETWORK SERVICE" -and $_ -ne "LOCAL SERVICE" -and $_ -ne "SYSTEM"} |
                    Sort-Object -Unique |
                    ForEach-Object { New-Object psobject -Property @{Computer=$Computer;LoggedOn=$_} } |
                    Select-Object Computer,LoggedOn
                }#If
        }
    catch
        {
            "Cannot find any processes running on $computer" | Out-Host
        }
     }#Forech-object(ComputerName)      
           
}#Process
End
{
}#End
}#Get-LoggedOnUser