获取操作系统是32还是64位

// 安全的取得真实系统信息
VOID SafeGetNativeSystemInfo(__out LPSYSTEM_INFO lpSystemInfo)
{
    if (NULL==lpSystemInfo)    return;
    typedef VOID (WINAPI *LPFN_GetNativeSystemInfo)(LPSYSTEM_INFO lpSystemInfo);
    LPFN_GetNativeSystemInfo fnGetNativeSystemInfo =         
    (LPFN_GetNativeSystemInfo)GetProcAddress( GetModuleHandle(_T("kernel32")),     
    "GetNativeSystemInfo");;
    if (NULL != fnGetNativeSystemInfo)
    {
        fnGetNativeSystemInfo(lpSystemInfo);
    }
    else
    {
        GetSystemInfo(lpSystemInfo);
    }
}


// 获取操作系统位数
int GetSystemBits()
{
    SYSTEM_INFO si;
    SafeGetNativeSystemInfo(&si);
    if (si.wProcessorArchitecture == PROCESSOR_ARCHITECTURE_AMD64 ||
        si.wProcessorArchitecture == PROCESSOR_ARCHITECTURE_IA64 )
    {
        return 64;
    }
    return 32;
}