#include <Windows.h>  
 #include <stdio.h>  
   

 DWORD readMBR()  
 {  
     DWORD dwBytesReturned;  
     BYTE pMBR[512]={0};  
   DWORD FSCTL_UNLOCK_VOLUME;
     
     //打开物理磁盘  
     HANDLE hDevice = CreateFile("\\\\.\\PhysicalDrive0", GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0, NULL);  
     if (hDevice == INVALID_HANDLE_VALUE)  
     {  
         printf("createfile failed...");  
         return -1;  
     }  
   
     
     DeviceIoControl(hDevice, FSCTL_LOCK_VOLUME, NULL, 0, NULL, 0, &dwBytesReturned, NULL);  
     //读磁盘文件   
     ReadFile(hDevice, pMBR, 512, &dwBytesReturned, NULL);  
     DeviceIoControl(hDevice, FSCTL_UNLOCK_VOLUME, NULL, 0, NULL, 0, &dwBytesReturned, NULL);  
     return 0;  
 }  
   
 int main(int argc, char* argv[])  
 {  

     readMBR();  
     return 0;  
 }
错误提示：C:\Windows\System32\hhhhh.cpp(20) : error C2065: 'FSCTL_LOCK_VOLUME' : undeclared identifier
搞了几次还是出错！