Question Modif clef sur +sieur serveur et pour +sieur user

[code:1]Foreach( $serveur IN (get-content $ini | where { ! $_ -match [String]::Empty }) ) [/code:1]

Ca marche

par contre
[code:1]Incomplete $(subexpression) sequence in string.
+ Write-Host \"$chaine -> $( $regKey1.GetValue(\"$ <<<< chaine\"«») )\"
Exception calling \"Substring\" with \"2\" argument(s): \"Index and length must refer to a location within the string.
Parameter name: length\"
+ if ( ($subkey.length -ge 8) -and ( $subkey.substring( <<<< ($subkey.length - 8), $subkey.length) -ine \"_Classes\" ) )
[/code:1]

[code:1]$computername = (get-wmiobject win32_computersystem).name

if ( \"$computername\" -ieq \"machineVlan1\" ) { $ini = \"D:\front_include_CA.ini\"}
if ( \"$computername\" -ieq \"machineVlan2\" ) { $ini = \"D:\middle_back_include_CA.ini\"}

$root = \"Users\"
#$root = \"LocalMachine\"
$type = [Microsoft.Win32.RegistryHive]::$root
#$key = \"SOFTWARE\Microsoft\Windows\CurrentVersion\"
$key = \"\"
$key_end = \"\Control Panel\Desktop\"
$chaine = \"ScreenSaveTimeOut\"
$value = 200

# pour chaque machine du fichier a partles lignes vides
Foreach( $serveur IN (get-content $ini | where { ! $_ -match [String]::Empty }) )
{
$regKey = [microsoft.win32.registrykey]::openremotebasekey($type, $serveur)
$regKey = $regKey.OpenSubKey($key)
Write-Host \"$serveur\"
Write-Host \"

---

\"
Foreach( $subkey in $regKey.GetSubKeyNames())
{
# on vire les clef \"*_Classes\"
if ( $subkey -notmatch \"_Classes\" )
{ #comme on a les user on va changer la valeur ici
Write-host -NoNewLine \"$subkey \"
$regKey1 = [microsoft.win32.registrykey]::openremotebasekey($type, $serveur)
$regKey1 = $regKey1.OpenSubKey(\"$subkey$key_end\"«»)
Write-Host \"$chaine = \" $regKey1.GetValue(\"$chaine\"«»)
}

}
#pause
Write-Host \"...\"
$null = $Host.UI.RawUI.ReadKey(\"NoEcho,IncludeKeyDown\"«»)
}
[/code:1]

ca marche :']
Merci

Qu'elles genre d'exceptions faut il gérer ? D'ailleurs quand on appelle une commande il y a moyen de savoir quelle Exception il y a trap ?