C# VirtualBox manager

using System;
using System.Collections.Generic;
using System.Text;
using System.Diagnostics;

namespace VirtualBoxManager
{
    class VirtualBoxManager
    {
        private String VMName;
        private String virtualBoxManage;

        public VirtualBoxManager(String VMName, String VirtualBoxManage)
        {
            this.VMName = VMName;
            this.virtualBoxManage = VirtualBoxManage;
        }

        private String launchVBoxManager(String args, String attendedOutput)
        {
            Process VBoxManage = new Process();
            VBoxManage.StartInfo.CreateNoWindow = true;
            VBoxManage.StartInfo.FileName = this.virtualBoxManage + "VBoxManage.exe";
            VBoxManage.StartInfo.WorkingDirectory = this.virtualBoxManage;
            VBoxManage.StartInfo.Arguments = args;
            VBoxManage.StartInfo.UseShellExecute = false;

            //We redirect output only if the user supply any attended output
            if (attendedOutput != "")
            {
                VBoxManage.StartInfo.RedirectStandardOutput = true;
            }
            VBoxManage.Start();

            //If we are waiting for an output, we wait until the end of the output
            if (attendedOutput != "")
            {
                String line = "";
                while (!VBoxManage.StandardOutput.EndOfStream)
                {
                    System.Windows.Forms.Application.DoEvents();
                    line = VBoxManage.StandardOutput.ReadToEnd();
                    if (line.Trim().StartsWith(attendedOutput))
                    {
                        return line.Trim();
                    }
                }
            }
            return "-1";
        }

        private String launchVBoxManager(String args)
        {
            return this.launchVBoxManager(args, "");
        }

        public void startVM()
        {
            launchVBoxManager(" startvm \"" + this.VMName + "\" --type headless");
        }

        public void stopVM()
        {
            launchVBoxManager(" controlvm \"" + this.VMName + "\" poweroff");
        }

        public String ipVM()
        {
            //Checking IP
            String ip = " guestproperty get \"" + this.VMName + "\" \"/VirtualBox/GuestInfo/Net/0/V4/IP\"";
            String tmpIP = launchVBoxManager(ip, "Value");
            if (tmpIP != "-1")
            {
                return tmpIP.Substring(7);
            }
            else
            {
                return "0.0.0.0";
            }
        }

        public Boolean statusVM(String login, String password)
        {
            String checkStatus = " guestcontrol \"" + this.VMName + "\" execute --image \"/bin/uname\" --username \"" + login + "\" --password \"" + password + "\" --wait-stdout";
            String checkStatusResult = "Linux";
            //Return the boolean result
            return (launchVBoxManager(checkStatus, checkStatusResult) == checkStatusResult);
        }
    }
}