Microsoft Office introduced several new file formats which can’t be read by older versions of the various Office products. I’m not sure why Microsoft decided to change the file formats but it is really a hassle for me. I’m running Office 2007 on my system while my girlfriend is still running an older version of Microsoft Office.
It happened twice already that she worked on my computer and saved a Microsoft Word format in the new format (.docx) and was not able to read the file on her computer. She does not have Internet access there which means that it was really problematic to get the right format on her computer.