All files open in the same window in Microsoft Excel

Issue

I have a problem with Excel 2007. All my files open in the same window.

Solution

• Go to explorer, choose tools, then folder options. Click the File Types tab.
• Scroll down to the XLS extension. Click the Advanced button. Choose "open", then click the edit button.
• At the end of the "Application used" entry, you'll probably see: /e
• After this, add: "%1" (be sure to include the quotes.)
• Then uncheck the "Use DDE" checkbox. Then click OK. (Windows re-checks it at some point for some reason, but it still works)
• Click on OK
• Now when you double-click a spreadsheet, it will open it in a new instance of Excel