List-LoggedInUsers.ps1

# Query Active Directory for computers running a Server operating system
$Servers = Get-ADComputer -Filter { OperatingSystem -like "*server*" }

# Loop through the list to query each server for login sessions
ForEach ($Server in $Servers) {
    $ServerName = $Server.Name

    # When running interactively, uncomment the Write-Host line below to show which server is being queried
    Write-Host "Querying $ServerName"

    if ((Test-Connection $ServerName -Count 1) 2> $null) {

        # Run the qwinsta.exe and parse the output
        $queryResults = (qwinsta /server:$ServerName | ForEach-Object { (($_.trim() -replace "\s+", ",")) } | ConvertFrom-Csv) 

        # Pull the session information from each instance
        ForEach ($queryResult in $queryResults) {
            $RDPUser = $queryResult.USERNAME
            $sessionType = $queryResult.SESSIONNAME

            # We only want to display where a "person" is logged in. Otherwise unused sessions show up as USERNAME as a number
            If (($RDPUser -match "[a-z]") -and ($null -ne $RDPUser)) { 
                # When running interactively, uncomment the Write-Host line below to show the output to screen
                # Write-Host $ServerName logged in by $RDPUser on $sessionType
                $SessionList = $SessionList + "`n`n" + $ServerName + " logged in by " + $RDPUser + " on " + $sessionType
            }
        }
    }
    else {
        Write-Host "$ServerName is not running"
    }
}


# When running interactively, uncomment the Write-Host line below to see the full list on screen
$SessionList