检测系统是否安装.NET Framework 3.5的方法

     
       //判断环境是否装了ie7，和net3.5
            RegistryKey key = Registry.LocalMachine;
            RegistryKey software = key.OpenSubKey("software\\Microsoft\\Internet Explorer\\Version Vector");
            if (!object.Equals(software, null))
            {
                version = software.GetValue("IE").ToString();
            }
            if (Convert.ToDouble(version) < 7.0000)
                ie();

            RegistryKey soft = key.OpenSubKey("software\\Microsoft\\NET Framework Setup\\NDP\\v3.5");
            if (!object.Equals(soft, null))
            {
                version = soft.GetValue("Version").ToString();
            }
            if (version == null)
                net();


  //是否安装ie
        private void ie()
        {
            System.Diagnostics.Process dir = new System.Diagnostics.Process();
            dir.StartInfo.UseShellExecute = false;

            ProcessStartInfo psi = new ProcessStartInfo();
            psi = new ProcessStartInfo();
            psi.FileName = Application.StartupPath + "/IE7.exe";
            Process pss = Process.Start(psi);