XLS and XLSX are the two file extension used by Microsoft Excel. Microsoft Excel 2003 documents are XLS while the 2007 edition works with XLSX format. Even if both formats belong to the same company you may have some trouble opening XLS files with the 2007 suite and XLSX data with the 2003 build. To avoid such a situation you can use Batch XLSX To XLS Converter.
This tool was designed to help you convert your Excel 2003 files to Excel 2007 files and vice-versa. It provides a powerful search tool that helps you look for all XLS or XLSX files in a folder and its subfolders.
So, using this application, you are able to easily convert only a selected file, or all Excel 2007 or 2003 files that are located in a certain folder. You can save the current project in a batch-xls2xls file, to save the job for a later time.
The program offers the possibility to pause the conversion process at any moment you want. Stopping the operation is also among the functions available in the application.
Batch XLSX To XLS Converter has an easy to use interface, with all the menus out in the open. With just a few clicks, you are able to select the files you want to convert.
The conversion process is very fast, taking just a few seconds of your time. While converting a number of 10 files, the CPU value peaked at 25 %, and only 4MB of RAM were required.
So, if you need a small yet powerful and fast XLSX to / from XLS converter you may take advantage of the trial period to see if this application provides all the features you need.

Limitations:
· Nag screen
· 30 days trial period