title: Will upgrading Office from 2003 to 2007 break VB programs which use Excel through the COM interop?
body: <p>Assume all traces of Office 2003 will be removed from the computer.</p>
  
  <p>UPDATE:</p>
  
  <p>I understand that I will still be able to use .xls files. I'm asking about automating Excel through the COM interop from outside Excel. When I add a reference to Excel to a VB project, it gives me a different version of the dll for different versions of Excel. If a program was compiled with a reference to Office 2003's dll, will it need to be recompiled for Office 2007? Will the code need to be updated to use the new dll?</p>