Step1: Tap the slide that you want to comment on.
Step2: The toolbar helps you create a new comment, delete the current comment, and navigate backward and forward through comments, reply to the current comment, or delete the current comment:
Step3: The Comment buttons in Windows Mobile: Create New Comment, Delete Current Comment, Go to Previous Comment, and Go to Next Comment
Step4: The Comments pane appears with a blank notation indicating your name and the date.
Step5: Type your comment. Tap elsewhere on the screen when you are done typing.
Step6: You can’t add comments in PowerPoint on a Windows tablet.