Process.Start()

ThreadPool.QueueUserWorkItem(delegate {
        Process process = Process.Start(startInfo);
        if(process.WaitForExit(timeout)) {
            // user exited
        } else {
            // timeout
        }
    });

public class UtilityManager
 {
      public Process UtilityProcess { get; private set; }
      private bool _isRunning;
      public UtilityManager() : this(null) {}
      public UtilityManager( Process process )
      {
          this. UtilityProcess = process ?? new Process();
          this._isRunning = false;
      }
      public void Start()
      {
          if (!_isRunning) {
          var startInfo = new ProcessStartInfo() {
              CreateNoWindow = true,
              UseShellExecute = true,
              FileName = _cmdLine,
              Arguments = _args
          };
          this.UtilityProcess.Start(startInfo);
          _isRunning = true;
      } else {
          throw new InvalidOperationException("Process already started");
      }
 }

[TestMethod]
 public void StartTest()
 {
      Process proc = new FakeProcess();  // May need to use a wrapper class
      UtilityManager manager = new UtilityManager( proc );
      manager.CommandLine = "command";
      ...

      manager.Start();

      Assert.IsTrue( proc.StartCalled );
      Assert.IsNotNull( proc.StartInfo );
      Assert.AreEqual( "command", proc.StartInfo.FileName );
      ...
 }