怎么隐藏winrar窗口

如何隐藏winrar窗口
cmd = string.Format("x {0} {1} -y",
                                    rarPath,
                                    SavePath);
                startinfo = new ProcessStartInfo();
                startinfo.FileName = rarexe;
                startinfo.Arguments = cmd;
                startinfo.WindowStyle = ProcessWindowStyle.Hidden;

                startinfo.WorkingDirectory = rarPath;
                process = new Process();
                process.StartInfo = startinfo;
                process.Start();
                process.WaitForExit();

调用winrar代码，但是无法隐藏winrar弹出的窗口。还请高手指点一下
[解决办法]
 ProcessStartInfo info = new ProcessStartInfo("rar.exe");
 string order = "e " + rarname + " -p" + sEnPWD + " -o+ " + strXmlSavePath;
 info.WindowStyle = ProcessWindowStyle.Hidden;
 info.Arguments = order;
 ...

我这样用的，没有显示winrar的界面啊
winrar 3.2版本