ReadHGlobalIntoStream has an issue with files over 4096 bytes.

[MWiz3]

Testing the ReadHGlobalIntoStream method I found my result had corrupted files if their size was over 4096 bytes.

I believe adding this line corrected the issue:

source = new IntPtr(source.ToInt64() + bytesToCopy);

So that the loop looks like:

int bytesToCopy;
for (int offset = 0; offset < length; offset += buffer.Length)
{
            //Copy buffer length or remaining length, whichever is smaller
            bytesToCopy = Math.Min(buffer.Length, length - offset);
            Marshal.Copy(source, buffer, 0, bytesToCopy);
            stream.Write(buffer, 0, bytesToCopy);
            source = new IntPtr(source.ToInt64() + bytesToCopy);
}