Как организовать параллельные процессы в С++ ?

#include <conio.h>
#include <iostream>
#include <windows.h>

using namespace std;

bool waitKey(const size_t secondsToWait)
{
    int i=secondsToWait*10;
    for(;(i)&&(!_kbhit());i--)
    {
         Sleep(100);
         if(i%10==0)
         {
             cout<<i/10<<endl;
         }
    }
    //очистка буфера клавиатуры
    while(_kbhit())
    {
        getch();
    }
    return(i);
}

int main()
{
  cout<<"press any key..."<<endl;
  if(waitKey(5))
  {
      cout<<"Countdown was stopped by key" << endl;
  }
  else
  {
      cout<<"Countdown was not stopped"<<endl;
  }
  return 0;
}