VC里判断系统是不是64bit

BOOL IsWow64() 
{ 
    typedef BOOL (WINAPI *LPFN_ISWOW64PROCESS) (HANDLE, PBOOL); 
    LPFN_ISWOW64PROCESS fnIsWow64Process; 
    BOOL bIsWow64 = FALSE; 
    fnIsWow64Process = (LPFN_ISWOW64PROCESS)GetProcAddress( GetModuleHandle("kernel32"),"IsWow64Process"); 
    if (NULL != fnIsWow64Process) 
    { 
        fnIsWow64Process(GetCurrentProcess(),&bIsWow64);
    } 
    return bIsWow64; 
}