New Office file formats were introduced in Microsoft Office 2007 which are also used in Office 2010. The new Office file formats include an x at the end of the previous extensions for example, the previous extension of Microsoft Word documents was .doc but now it’s .docx while the extension for Microsoft Excel was .xls but now with Office 2007 and 2010, it has become .xlsx.
The new file format includes some new features that were not present in the previous file format. The new files have a lot less size compared to the previous ones. Since some of the features of the new file format are disabled if you open a file that was created with the previous version of Microsoft Office earlier than Office 2007, you may need to convert it to the new format in order to enable all the features.
Converting a previous file format to Office 2007, 2010 file format is relatively easy. Just open the file in Office 2007 or 2010 and click on File Menu. In the Info tab, you’ll see the file is being shown as in Compatibility mode. You can press the Convert button to convert the document to the latest format.
When you press the Convert button, a dialog box will appear stating the following:
This action converts the workbook to the current file format, which allows you to use all the new features of Excel, and it reduces the file size. The original workbook will be deleted and cannot be restored after this conversion.
Just press OK to continue with the conversion. Please note that the steps may not be the same for Office 2007 and Office 2010 but are similar to the steps given above. You can also convert the document by using Save As function.