<?xml version="1.0" encoding="utf-8">
<configuration>
    <userSettings>
          <sektion.Properties.Settings>
               <setting name="Einstellung1" serializeAs="String">
                   <value>false</value>
               </setting>
               <setting name="Einstellung2" serializeAs="String">
                   <value>true</value>
               </setting>
usw. 

function PrepareToInstall(var NeedsRestart: Boolean): String;
 
var
  XMLDoc : Variant;
  path, XMLFileName: string;
 
Begin
{ Load the XML File }
  path :='c:\test\';
  XMLFileName :='test.xml';
  XMLDoc := CreateOleObject('MSXML2.DOMDocument');
  XMLDoc.async := False;
  XMLDoc.resolveExternals := False;
  XMLDoc.load(Path + XMLFileName);
 
 if XMLDoc.parseError.errorCode <> 0 then
    RaiseException('Error in xml on line ' + IntToStr(XMLDoc.parseError.line) + ', position ' + IntToStr(XMLDoc.parseError.linepos) + ': ' + XMLDoc.parseError.reason);
 
  MsgBox('Loaded the XML file.', mbInformation, mb_Ok);
 
  { Modify the XML document - aber wie? }
 
  { Save the XML document }
 
  XMLDoc.Save(Path + XMLFileName);
 
end; 

[Icons]
Name: {userdesktop}\{cm:MyAppName}; Filename: {app}\bin\Test.exe; WorkingDir: {app}; Tasks: desktopicon; 

[Files]
Source: "F:\Visual Studio 2008\Projects\ZI\dbk.txt"; DestDir: "{app}"; Flags: {code:FileFlag}
[Registry]
Root:HKLM; Subkey: "Software\ZI"; ValueType: dword; ValueName:"S1";ValueData:"999";Flags: {code:RegFlag}

[Code]
var Unprotected:boolean;    //Merken wenn ungeschützt und ablauf ändern

function RegFlag(dummy:string):dword
begin
  if(Unprotected)then
    result:=dontcreatekey;
  else 
    result:=uninsdeletevalue;
end

function FileFlag(dummy:string):dword
begin
  if(Unprotected)then
    result:=ignoreversion;
  else 
    result:=dontcopy;
end
...