Maps the w3p#n to the name of the app pool.

map-w3wp-to-webapp.ps1

$count = (Get-Process | Where-Object { $_.Name -eq 'w3wp' }).count -1
$var = 1
$result = ''

$id = (Get-Counter "\Process(w3wp)\ID Process").CounterSamples.CookedValue
$app = [regex]::match((Get-CimInstance Win32_Process -Filter "ProcessId = $id").CommandLine, '"([^"]+)"').Groups[1].Value
$result += "w3wp = $id, $app`n"

while ($var -le $count) {
    $id = (Get-Counter "\Process(w3wp#$var)\ID Process").CounterSamples.CookedValue
    $app = [regex]::match((Get-CimInstance Win32_Process -Filter "ProcessId = $id").CommandLine, '"([^"]+)"').Groups[1].Value
    $result += "w3wp#$var = $id, $app`n"
    $var += 1
}
$result