Why? Because:
Here's a rundown of the key features and enhancements in the v4.04.03 (2012 Update):
: Designed to convert "orphaned" or corrupted OST files when the original Exchange Server was no longer available.
The standard version (v4.x) often had limitations on data volume in its trial mode, while the professional/business license removed these caps and added advanced features like direct migration to Office 365 or Live Exchange. comparison with current modern versions of this tool? OST Repair By OST to PST Converter Tool - Google Groups