its a string of bytes in an
  executable file.  The second one edits machine instructions to alter
  the behaviour of the program.  Both examples provided in the next
  two sections can be reproduced on MS-DOS version 6.22.  These
  examples can be performed on Windows 98 too after minor adjustments.
</p>
<h2 id="editing-data">Editing Data</h2>
<p>
  Let us first see an example of editing an error message produced by
  the <code>MODE</code> command.  This DOS command is used for
  displaying and reconfiguri