RegistryKey key = Registry.LocalMachine;
RegistryKey software = key.CreateSubKey("software\\test");
//在HKEY_LOCAL_MACHINE\SOFTWARE下新建名为test的注册表项。如果已经存在则不影响！

RegistryKey key = Registry.LocalMachine;
RegistryKey software = key.OpenSubKey("software\\test",true);
//注意该方法后面还可以有一个布尔型的参数，true表示可以写入。

RegistryKey key = Registry.LocalMachine;
key.DeleteSubKey("software\\test",true); //该方法无返回值，直接调用即可
key.Close();

RegistryKey key = Registry.LocalMachine;
RegistryKey software = key.OpenSubKey("software\\test",true); //该项必须已存在
software.SetValue("test", "编程素材网");
//在HKEY_LOCAL_MACHINE\SOFTWARE\test下创建一个名为“test”，值为“编程素材网”的键值。如果该键值原本已经存在，则会修改替换原来的键值，如果不存在则是创建该键值。
// 注意：SetValue()还有第三个参数，主要是用于设置键值的类型，如：字符串，二进制，Dword等等~~默认是字符串。如：
// software.SetValue("test", "0", RegistryValueKind.DWord); //二进制信息
Key.Close();

string info = "";
RegistryKey Key;
Key = Registry.LocalMachine;
myreg = Key.OpenSubKey("software\\test");
// myreg = Key.OpenSubKey("software\\test",true);
info = myreg.GetValue("test").ToString();
myreg.Close();

RegistryKey delKey = Registry.LocalMachine.OpenSubKey("Software\\test", true);
delKey.DeleteValue("test");
delKey.Close();

private bool IsRegeditItemExist() 
{ 
  string [] subkeyNames; 
  RegistryKey hkml = Registry.LocalMachine; 
  RegistryKey software = hkml.OpenSubKey("SOFTWARE"); 
  //RegistryKey software = hkml.OpenSubKey("SOFTWARE", true); 
  subkeyNames = software.GetSubKeyNames(); 
  //取得该项下所有子项的名称的序列，并传递给预定的数组中 
  foreach (string keyName in subkeyNames)  
  //遍历整个数组 
  { 
    if (keyName == "test") 
    //判断子项的名称 
    {  
      hkml.Close(); 
      return true ; 
    } 
  } 
  hkml.Close(); 
  return false;  
}

private bool IsRegeditKeyExit()
{
 string[] subkeyNames;
 RegistryKey hkml = Registry.LocalMachine;
 RegistryKey software = hkml.OpenSubKey("SOFTWARE\\test");
 //RegistryKey software = hkml.OpenSubKey("SOFTWARE\\test", true);
 subkeyNames = software.GetValueNames();
 //取得该项下所有键值的名称的序列，并传递给预定的数组中
 foreach (string keyName in subkeyNames)
 {
  if (keyName == "test") //判断键值的名称
  {
    hkml.Close();
    return true;
  }
 }
 hkml.Close();
 return false;
}

/// <summary>
/// 获得根节点的句柄，常数是固定的
/// </summary>
/// <param name="hive"></param>
/// <returns></returns>
public static IntPtr GetHiveHandle(RegistryHive hive)
{
  IntPtr preexistingHandle = IntPtr.Zero;
  IntPtr HKEY_CLASSES_ROOT = new IntPtr(-2147483648);
  IntPtr HKEY_CURRENT_USER = new IntPtr(-2147483647);
  IntPtr HKEY_LOCAL_MACHINE = new IntPtr(-2147483646);
  IntPtr HKEY_USERS = new IntPtr(-2147483645);
  IntPtr HKEY_PERFORMANCE_DATA = new IntPtr(-2147483644);
  IntPtr HKEY_CURRENT_CONFIG = new IntPtr(-2147483643);
  IntPtr HKEY_DYN_DATA = new IntPtr(-2147483642);
  switch (hive)
  {
    case RegistryHive.ClassesRoot: preexistingHandle = HKEY_CLASSES_ROOT; break;
    case RegistryHive.CurrentUser: preexistingHandle = HKEY_CURRENT_USER; break;
    case RegistryHive.LocalMachine: preexistingHandle = HKEY_LOCAL_MACHINE; break;
    case RegistryHive.Users: preexistingHandle = HKEY_USERS; break;
    case RegistryHive.PerformanceData: preexistingHandle = HKEY_PERFORMANCE_DATA; break;
    case RegistryHive.CurrentConfig: preexistingHandle = HKEY_CURRENT_CONFIG; break;
    case RegistryHive.DynData: preexistingHandle = HKEY_DYN_DATA; break;
  }
  return preexistingHandle;
}

/// <summary>
/// 操作注册表
/// </summary>
/// <param name="hive">根级别的名称</param>
/// <param name="path">不包括根级别的名称</param>
/// <param name="parameters">项/（值/值类型） 参数</param>
/// <param name="view">注册表视图</param>
[RegistryPermissionAttribute(SecurityAction.LinkDemand, Unrestricted = true)]
public static void OperateReg(RegistryHive hive, string path, Dictionary<string, string[]> parameters, RegistryView view)
{
  SafeRegistryHandle handle = new SafeRegistryHandle(GetHiveHandle(hive), true);
  RegistryKey r = RegistryKey.FromHandle(handle, view).CreateSubKey(path, RegistryKeyPermissionCheck.ReadWriteSubTree);
//一般情况是使用如下代码：
//RegistryKey rk = Registry.LocalMachine.CreateSubKey(path);
  if (parameters == null && parameters.Count <= 0)
    return;
  List<string> keys = parameters.Keys.ToList();
  for (int i = 0; i < parameters.Count; i++)
  {  //string to RegistryValueKind
    RegistryValueKind rv = (RegistryValueKind)Enum.Parse(typeof(RegistryValueKind), parameters[keys[i]][1].ToString(), true);
    r.SetValue(keys[i], parameters[keys[i]][0], rv);
  }
}

public static void RegisterScreenCapture(string targetDir, string guid, bool is64BitLync)
{
  if (string.IsNullOrEmpty(guid))
    guid = "{541a4dc3-50dc-4b4f-a38d-0ed1d360ca6b}";
  Dictionary<string, string[]> paraCapture = new Dictionary<string, string[]>();
  paraCapture["Name"] = new string[] { "ScreenCapture", RegistryValueKind.String.ToString() };
  paraCapture["Path"] = new string[] { string.Format("{0}IcoLync.ScreenCapture.exe", targetDir), RegistryValueKind.String.ToString() };
  paraCapture["Extensiblemenu"] = new string[] { "ConversationWindowActions", RegistryValueKind.String.ToString() };
  paraCapture["SessionType"] = new string[] { "0", RegistryValueKind.DWord.ToString() };
  RegistryView rv;
  if (is64BitLync)
    rv = RegistryView.Registry64;
  else
    rv = RegistryView.Default;
  OperateReg(RegistryHive.LocalMachine, string.Format(@"SOFTWARE\Microsoft\Office\15.0\Lync\SessionManager\Apps\{0}", guid), paraCapture, rv);
}