Getting problem with timing in C in visual studio 2010

I have a function for getting system time. The function is defined as follows.

  int getSystemTime(struct timeval tv, void * tz);{
  DWORD milliseconds;
  milliseconds = timeGetTime();
  tv->tv_sec = milliseconds / 1000;
  tv->tv_usec = (milliseconds % 1000) * 1000;
  return 0;
  }

Precisely following are the problems:

 1.error: identifier DWORD is undentified .
 2.error: identifier timeGetTime() is undefined.
 3.error: identifier suseconds_t is undefined. 

I tried to include windef.h where DWORD is defined. But the problem is, I got开发者_StackOverflow社区 the error like:

 1. error: identifier PCONTEXT is undefined.

The header file for time included is time.h. Here the timeval defined is:

#ifndef _WINSOCK_H
struct timeval {
time_t tv_sec;
suseconds_t tv_usec;
};

Could you please tell me what shall I do to make this function run in windows environment?

[EDIT]

 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif

#ifdef HAVE_WINDOWS_H
#include <windows.h>
#endif

#ifdef HAVE_MMSYSTEM_H
#include <mmsystem.h>
#endif

#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>

You need to include windows.h at the top of your C file.