Opening spreadsheets in separate windows

[Harambe]

How can I set Excel to open spreadsheets in separate windows when opening new/previously saved spreadsheets? Currently I have two work laptops, main laptop opens each spreadsheet into its own window. Alternate opens each spreadsheet into one window, main laptop is running Office 2013 alternate is running 2010. I don't want to do any registry edits, doing so would require admin access and I doubt company would go for the modification. I want to avoid the steps of having to open a blank spreadsheet then manually finding and opening that spreadsheet just to have more than one window open.

Thanks in advance.