typedef struct _SYSTEM_INFO {
    union {
        DWORD dwOemId;          
        struct {
            WORD wProcessorArchitecture;
            WORD wReserved;
        };
    };
    DWORD dwPageSize;
    LPVOID lpMinimumApplicationAddress;
    LPVOID lpMaximumApplicationAddress;
    DWORD_PTR dwActiveProcessorMask;
    DWORD dwNumberOfProcessors;
    DWORD dwProcessorType;
    DWORD dwAllocationGranularity;
    WORD wProcessorLevel;
    WORD wProcessorRevision;
} SYSTEM_INFO, *LPSYSTEM_INFO;