Multiple Excel Files Open on Multiple Tabs, Instead of One Tab - Microsoft Community

Multiple Excel Files Open on Multiple Tabs, Instead of One Tab - Microsoft Community

Another option is to right-click the Excel taskbar button and to select Microsoft Office Excel 2010 from the popup menu.

If you want to view workbooks on two screens, you'll have to start two separate instances of Excel. Start Excel, then Shift+click the Excel icon on the Windows taskbar to open a second instance, and drag the new window to the other screen (if it is maximized, un-maximize the window first).