Sure, I can help you with that! Here are the steps to set Excel 2010 as the default program for opening Excel files:

1. Right-click on any Excel file that you want to open with Excel 2010.
2. Click on "Open With" and then select "Choose Default Program".
3. In the "Open With" dialog box, select "Microsoft Excel 2010" from the list of programs.
4. Check the box that says "Always use the selected program to open this kind of file".
5. Click "OK" to save the changes.

That's it! Now, whenever you double-click on an Excel file, it should automatically open in Excel 2010. If you have any other questions, feel free to ask!