hello, i'm new at C Programming (i learned c++) i want to create a process with windows.h

at first i just want to start my main programm that creates a process ( --> starts an other programm)

that's my code, but it doesn't really work, i removed every unnessasery line of code but "void sleep(700)" (or "sleep (700)" for testing if the windows methods work, but i get an error, that "sleep" cant be found.

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

using namespace std;

void main()
{

//bool ret;
//startupinfo stupinfo;
//prozess_information pro2info;
//Getstartupinfo (&stupinfo);

 //createprozess(null, "C:\\bsss10\\betriebssystemePRA1.exe", null, null, false, create_new_console, null,
 // null, &stupinfo, &pro2info);

 sleep (700);

cout<< "hello";

}

thanks in advance