typedef struct _MCA_EXCEPTION
{
     ULONG VersionNumber;
     MCA_EXCEPTION_TYPE ExceptionType;
     LARGE_INTEGER TimeStamp;
     ULONG ProcessorNumber;
     ULONG Reserved1;
     BYTE u[32];
     ULONG ExtCnt;
     ULONG Reserved3;
     UINT64 ExtReg[24];
} MCA_EXCEPTION, *PMCA_EXCEPTION;

Windows Vista Kernel Structures