problem in programing

hi , i bought a new computer that runs on win-xp , x64 edition only , cuz of high hardware quality and performance , but now when i try to program
everything goes well except some functions like this one:
[code]
void full ()
{
keybd_event(VK_MENU,0x*8,0,0);
keybd_event(VK_RETURN,0x*c,0,0);
keybd_event(VK_RETURN,0x*c,KEYEVENTF_KEYUP,0);
keybd_event(VK_MENU,0x*8,KEYEVENTF_KEYUP,0);
}
[/code]
it should make me a full screen
but it doesn't!
i tryed to compile it with a simple hello-world program
[code]
#include<iostream>
#include<cstdlib>
#include<string>
#include<ctime>
#include<conio.h>
#include<windows.h>
using namespace std;

void full ()
{
keybd_event(VK_MENU,0x*8,0,0);
keybd_event(VK_RETURN,0x*c,0,0);
keybd_event(VK_RETURN,0x*c,KEYEVENTF_KEYUP,0);
keybd_event(VK_MENU,0x*8,KEYEVENTF_KEYUP,0);
}

int TimeWaster(int a)
{
a=a**00;
for(int i =0; i <= a; i++ )
cout<<"\b";
}

int main()
{
full();
cout <<" Hello World " << endl;
Sleep(*00);
TimeWaster(200);
cout <<" Press Any Key To Continue... " << endl;
cin.get();
return 0;
}
[/code] and still not working.... is it an OS problem or just the function...?