typedef struct _MEMORYSTATUS {
    DWORD dwLength;
    DWORD dwMemoryLoad;
    SIZE_T dwTotalPhys;
    SIZE_T dwAvailPhys;
    SIZE_T dwTotalPageFile;
    SIZE_T dwAvailPageFile;
    SIZE_T dwTotalVirtual;
    SIZE_T dwAvailVirtual;
} MEMORYSTATUS, *LPMEMORYSTATUS;