I have to open several workbooks at once (like maybe 20). When I do the list of files are listed vertical when I hover over the 'excel' icon on the taskbar. I'll make a change to a workbook and then close it. When I get down to about 10 workbooks, the listing changes from vertical to horizontal with little preview windows. Does anybody know how to disable this behavior and just keep the vertical list of files? This is on Excel 2016 btw.