A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data
Dear Tylereb,
Thank you for posting in Microsoft Community.
Based on the description, you cannot open .dif file in Excel application. Before moving forward, we need more detailed information about the situation you are experiencing.
May I know what version of Excel application you're using and what operating system?
Can you please try to open Excel application > File tab > Open > This PC > choose All files > locate your .dif file and open it.
Hope the suggestion can help you.
We look forward to your response. Thanks for your cooperation. Stay safe and healthy always.
Sincerely,
Zee | Microsoft Community Moderator