C ++ - 如何指定MBR的偏移量？

Question

我能够修改MBR被0值覆盖。但是，是否有可能使我只覆盖MBR（Boot Signature）的最后2个字节（55h AAh）变为00h 00h？ 我的代码是：

char dataWrite[3] = "\x00\x00";

// Create file of physical drive
HANDLE MasterBootRecord = CreateFile("\\\\.\\PhysicalDrive0"
    , GENERIC_ALL, FILE_SHARE_READ | FILE_SHARE_WRITE
    , NULL, OPEN_EXISTING, NULL, NULL);


// Set file pointer
DWORD dwPtr1 = SetFilePointer(MasterBootRecord, 510, NULL, NULL);

if (dwPtr1 == INVALID_SET_FILE_POINTER) // Test for failure
{
    cout<< "\n\nSetFilePointer Failed to write,Err No: "<< GetLastError();
    Sleep(5000);
    ExitProcess(0);
} 

// Write to file
if (WriteFile(MasterBootRecord, dataWrite, 512, &write, NULL)) {
    cout << "Boot signature overwritten." << endl;
    Sleep(5000);
    ExitProcess(0);
} else...

结果证明成功但写入MBR的值是错误的。我对C ++很陌生，因此对此有点困惑。任何帮助将不胜感激。感谢