Click the top "View" tab and click "Normal" from the Workbook Views group to return to Normal view. Click the appropriate sheet name at the bottom-left of Excel 2007 to return to a specific sheet.

You can change views in Excel depending on what you're doing and what you want to see. Learn how in this step-by-step tutorial.

Here are a few default Excel settings you should change for a better experience if the default Excel interface is not to your liking.