OpenProcess returns NULL every time in c++? - c++

Question

I "copied" a simple code snippet from a site and adjusted it to a game I was trying to hack. An old game with no multiplayer, basically just to practice all this memory editing stuff. Every time my program successfully returns a window handle, but then fails to return the process handle. Here is my code:
#include "stdafx.h"
#include <iostream>
#include <Windows.h>
using namespace std;
int _tmain(int argc, _TCHAR* argv[])
{
long address = 0x47C0F04;
int newvalue = 200;
DWORD newvaluesize = sizeof(newvalue);
HWND hWnd = FindWindow(0, L"No One Lives Forever");
HANDLE pHandle;
DWORD pid;
if(hWnd != 0) {
cout << "Found windowx.\n";
GetWindowThreadProcessId(hWnd, &pid);
pHandle = OpenProcess(PROCESS_ALL_ACCESS, FALSE, pid);
}
else {
cout << "Can't find window\n";
}
if(pHandle !=0) {
WriteProcessMemory(pHandle, (LPVOID)address, (LPVOID)newvalue, newvaluesize, 0);
cout << "Written to memory successfully\n";
}
else {
cout << "Couldn't get handle.\n";
}
CloseHandle(pHandle);
return 0;
}
The game is from 2000 if I recall correctly (really awesome game by the way) so I'm assuming it doesn't have any advanced anti-hack shield, since I can also pretty much edit the value of that address in cheat engine and it works with no hassle.
EDIT: I'll just explain what exactly happens. It always prints "Found window" but then it directly prints "Couldn't get handle". I don't get any compiler errors (I'm compiling in Microsoft Visual C++ 2010 Express)

Answer 1

You must run your program as administrator to get a handle with PROCESS_ALL_ACCESS permissions, this will fix your problem.

Answer 2

As GuidedHacking mentioned you need to run program as Admin ,Use this code to check whether your process is running as Admin rights.
BOOL IsElevatedProcess()
{
BOOL is_elevated = FALSE;
HANDLE token = NULL;
if (GT_IsPrivateMethod(gt_private_method, FUNC_NAME, LINE_NO))
{
if (OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY, &token))
{
TOKEN_ELEVATION elevation;
DWORD token_sz = sizeof(TOKEN_ELEVATION);
if (GetTokenInformation(token, TokenElevation, &elevation, sizeof(elevation), &token_sz))
{
is_elevated = elevation.TokenIsElevated;
}
}
if (token)
{
CloseHandle(token);
}
}
return is_elevated;
}