Displaying comments in excel

I have a created a spreadsheet in the desktop version of Excel containing cell comments. My colleague uses the online version and when he loads up the spreadsheet his screen is dividend in two, with the spreadsheet cells on the left hand side and bar with comments in on the right. This bar allows him to view, create & edit comments, like the debug screen. In Excel online he doesn't see "red" tabs on cells but instead comments are displayed in the bar on the right hand side. How do I create a similar view in my PC version of Excel?