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copied!<p>Your buffer is the size of 10 ints, which is 40 bytes on Windows. You are trying to write 100,000 bytes from that buffer. That is undefined behaviour, a buffer overrun. Hence the access violation.</p> <p>You must not pass a value greater than <code>sizeof(test_buffer)</code>, i.e. <code>40</code>, to the <code>nNumberOfBytesToWrite</code> parameter of <code>WriteFile</code>.</p> <p>You'll need to write this file in a loop, writing 40 bytes at a time, until you have written as much as you need. Perhaps something like this:</p> <pre><code>BOOL bSuccess = TRUE; DWORD bytesRemaining = 100000; while (bSuccess && bytesRemaining>0) { DWORD bytesToWrite = std::min(sizeof(test_buffer), bytesRemaining); DWORD bytesWritten; bSuccess = WriteFile(hFile, test_buffer, bytesToWrite, &bytesWritten, NULL); bytesRemaining -= bytesToWrite; } if (!bSuccess) { //handle error; } </code></pre> <p>Writing 40 bytes at a time is pretty slow. You'll find it more efficient to write a few KB with each call to <code>WriteFile</code>.</p> <p>Note that you aren't allowed to pass <code>NULL</code> to the <code>lpNumberOfBytesWritten</code> parameter if you also pass <code>NULL</code> to <code>lpOverlapped</code>, as you do here. From the <a href="http://msdn.microsoft.com/en-us/library/windows/desktop/aa365747.aspx" rel="nofollow">documentation</a>:</p> <blockquote> <p><em>lpNumberOfBytesWritten</em> [out, optional]</p> <p>......</p> <p>This parameter can be NULL only when the lpOverlapped parameter is not NULL.</p> </blockquote>

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