Powershell: Registry-Wert setzen

Property 'InitialSize' cannot be found on this object; make sure it exists and is settable.
At C:\Dokumente und Einstellungen\XPMUser\Eigene Dateien\PowerShell\Scripts\regkeywrite2.ps1:2 char:5
+ $pf. <<<< InitialSize = [int]4000
    + CategoryInfo          : InvalidOperation: (:) , RuntimeException
    + FullyQualifiedErrorId : PropertyAssignmentException

Property 'MaximumSize' cannot be found on this object; make sure it exists and is settable.
At C:\Dokumente und Einstellungen\XPMUser\Eigene Dateien\PowerShell\Scripts\regkeywrite2.ps1:3 char:5
+ $pf. <<<< MaximumSize = [int]4000
    + CategoryInfo          : InvalidOperation: (:) , RuntimeException
    + FullyQualifiedErrorId : PropertyAssignmentException

Method invocation failed because [System.Object[]] doesn't contain a method named 'Put'.
At C:\Dokumente und Einstellungen\XPMUser\Eigene Dateien\PowerShell\Scripts\regkeywrite2.ps1:4 char:8
+ $pf.Put <<<< ()
    + CategoryInfo          : InvalidOperation: (Put:String) , RuntimeException
    + FullyQualifiedErrorId : MethodNotFound

PS C:\Dokumente und Einstellungen\XPMUser\Eigene Dateien\PowerShell\Scripts> Get-WMIObject -Class "Win32_PageFileSetting"  | gm


   TypeName: System.Management.ManagementObject#root\cimv2\Win32_PageFileSetting

Name                MemberType   Definition
----                ----------   ----------
Caption             Property     System.String Caption {get;set;}
Description         Property     System.String Description {get;set;}
InitialSize         Property     System.UInt32 InitialSize {get;set;}
MaximumSize         Property     System.UInt32 MaximumSize {get;set;}
Name                Property     System.String Name {get;set;}
SettingID           Property     System.String SettingID {get;set;}
__CLASS             Property     System.String __CLASS {get;set;}
__DERIVATION        Property     System.String __DERIVATION {get;set;}
__DYNASTY           Property     System.String __DYNASTY {get;set;}
__GENUS             Property     System.Int32 __GENUS {get;set;}
__NAMESPACE         Property     System.String __NAMESPACE {get;set;}
__PATH              Property     System.String __PATH {get;set;}
__PROPERTY_COUNT    Property     System.Int32 __PROPERTY_COUNT {get;set;}
__RELPATH           Property     System.String __RELPATH {get;set;}
__SERVER            Property     System.String __SERVER {get;set;}
__SUPERCLASS        Property     System.String __SUPERCLASS {get;set;}
ConvertFromDateTime ScriptMethod System.Object ConvertFromDateTime();
ConvertToDateTime   ScriptMethod System.Object ConvertToDateTime();