title: Converting lots of files from xls to xlsx with Microsoft Compatibility Pack
body: <p>I was looking for a way to convert a huge number of files from xls to xlsx programatically , and I actually found a way which did not require pay-to-use libraries - the Microsoft Compatibility Pack. </p>
  
  <pre><code>Process.Start(@"c:\Program Files (x86)\Microsoft Office\Office12\excelcnv.exe", string.Format(@" -nme -oice {0} {1}", filename, destinationFilename))
  </code></pre>
  
  <p>However, I encountered an issue while converting a huge number of files basically I was iterating over a list of filepaths and running this code, eventually I ended up creating a process for every file I wanted to convert and almost killed my machine.  Can I somehow use one process for a number of files ? </p>