Read specific sector on hard drive using C language on windows

Question

i have tried this code it works when i read a sector from an USB flash drive but it does\'nt work with any partiton on hard drive , so i want to know if it\'s the same thing

Answer 1

The problem is the sharing mode. You have specified FILE_SHARE_READ which means that nobody else is allowed to write to the device, but the partition is already mounted read/write so it isn't possible to give you that sharing mode. If you use FILE_SHARE_READ|FILE_SHARE_WRITE it will work. (Well, provided the disk sector size is 512 bytes, and provided the process is running with administrator privilege.)

You're also checking for failure incorrectly; CreateFile returns INVALID_HANDLE_VALUE on failure rather than NULL.

I tested this code successfully:

#include 

#include 

int main(int argc, char ** argv)
{
    int retCode = 0;
    BYTE sector[512];
    DWORD bytesRead;
    HANDLE device = NULL;
    int numSector = 5;

    device = CreateFile(L"\\\\.\\C:",    // Drive to open
                        GENERIC_READ,           // Access mode
                        FILE_SHARE_READ|FILE_SHARE_WRITE,        // Share Mode
                        NULL,                   // Security Descriptor
                        OPEN_EXISTING,          // How to create
                        0,                      // File attributes
                        NULL);                  // Handle to template

    if(device == INVALID_HANDLE_VALUE)
    {
        printf("CreateFile: %u\n", GetLastError());
        return 1;
    }

    SetFilePointer (device, numSector*512, NULL, FILE_BEGIN) ;

    if (!ReadFile(device, sector, 512, &bytesRead, NULL))
    {
        printf("ReadFile: %u\n", GetLastError());
    }
    else
    {
        printf("Success!\n");
    }

    return 0;
}