Running your apps on a hidden desktop

Here’s a technique to run a GUI application in a hidden manner. It’s not a big deal really and is not meant for espionage or any such activity; rather it’s just an useful trick to know if you want to run a desktop game when you are at work and you don’t want your boss to see it. Basically we create a second desktop, switch to it, and run our apps on it.

bool RunAppInDesktop(
    const char* szDesktop, //A name for the new desktop
    const char* szAppPath, //Fully qualified path to your app
    bool bPrompt = false   //Set true to get a mock messagebox
);

If the bPrompt parameter is false, the new app is spawned on the new desktop and we switch back to the current desktop quickly; if you set it to true, the mock messagebox pops up and remains on screen preventing the new desktop from closing. Play your games or watch you videos or whatever and when your boss comes near you, close the messagebox to go back to the default desktop. When he/she leaves, switch back again and your apps will be still running there just as you had left them – like obedient little puppies 🙂

When you are done, close all the apps and then dismiss the messagebox; the second desktop will now be closed and destroyed.

Here is the full code listing :-

bool RunAppInDesktop(const char* szDesktop,
  const char* szAppPath, bool bPrompt = false);

//... your code goes here

bool RunAppInDesktop(const char* szDesktop,
           const char* szAppPath,
           bool bPrompt /*= false*/)
{
  bool ret = true;
  HDESK horig = GetThreadDesktop(GetCurrentThreadId());
  HDESK hdesk = CreateDesktop(szDesktop,NULL,NULL,
    0,GENERIC_ALL,NULL);
  if(hdesk)
  {
    if(SetThreadDesktop(hdesk))
    {
      SwitchDesktop(hdesk);
      PROCESS_INFORMATION ProcessInfo;
      STARTUPINFO StartupInfo;
      ZeroMemory(&StartupInfo, sizeof(StartupInfo));
      StartupInfo.cb = sizeof StartupInfo ;
      char tmp[1024];
      strcpy(tmp,szDesktop);
      StartupInfo.lpDesktop = tmp;
      if(CreateProcess(szAppPath, NULL,
        NULL,NULL,FALSE,0,NULL,
        NULL,&StartupInfo,&ProcessInfo))
      {
        CloseHandle(ProcessInfo.hThread);
        CloseHandle(ProcessInfo.hProcess);
      }
      else
        ret = false;
      if(bPrompt)
        MessageBox(NULL,"Close all your apps now",
          "Prompt",MB_OK);
      else
        Sleep(300);
      SwitchDesktop(horig);
      SetThreadDesktop(horig);
    }
    else
      ret = false;
  }
  else
    ret = false;
  CloseDesktop(hdesk);
  return ret;
}