//1.向注册表中写信息
using (RegistryKey key = Registry.LocalMachine.OpenSubKey(@"", true))
{
　　if (key == null)
　　{
　　　　using (RegistryKey myKey = Registry.LocalMachine.CreateSubKey(@"SOFTWARE\EricSun\MyTestKey"))
　　　　{
　　　　　　myKey.SetValue("MyKeyName", "Hello EricSun." + DateTime.Now.ToString());
　　　　}
　　}
　　else
　　{
　　　　key.SetValue("MyKeyName", "Hello EricSun." + DateTime.Now.ToString());
　　}
}

//2.读取信息(IIS也可以正常读取)

protected string GetRegistryValue(string path, string paramName)
{
　　string value = string.Empty;
      RegistryKey root = Registry.LocalMachine;
      RegistryKey rk = root.OpenSubKey(path);
      if (rk != null)
      {
      　　value = (string)rk.GetValue(paramName, null);
      }
      return value;
}

string value = GetRegistryValue("SOFTWARE\\EricSun\\MyTestKey", "MyKeyName");

Response.Write(value);