How can I restore an unsaved excel file?

Welcome to the forums!

Perhaps - if you launch Excel (the application itself, not the original document) it may generate a Recovered Document file which hopefully will contain your data. This depends on your preferences settings in Excel, how close to the time you shut down you made the changes, and how you shut down.

If you shut down 'properly' and were presented with a dialog box asking if you wanted to save the file, and you clicked Don't Save, you are out of luck.

You can set the autosave preferences in Excel (or any Office app) in Preferences > Save, check the box for Save Autorecover Info and set a time (the default for this is checked, with a 10 minute interval).

Hope this helps...