I get asked this question all the time:

Sometimes downloads will open within your internet browser, but look like an Excel document. You can easily adjust your computer’s default settings so these types of files will always open directly in Excel.
To do this, please find the instructions for the type of computer and browser you use, and then complete the related steps.

For PC (Windows) Users:
1. On your desktop, click ‘My Computer’.
2. Click ‘Tools’.
3. Click ‘Folder Options’.
4. Click ‘File Types’.
5. Find the file type ‘.xls’ in the list and highlight it.
6. Click ‘Advanced’.
7. De-select ‘Browse in same window’.
8. Click ‘OK’.
9. Click ‘Close’