PowerPoint does not have a Track Changes feature the same as the one in Microsoft Word although there are a few alternatives that you can try.
The Reviewing toolbar was added in PowerPoint 2002.
You can add comments to individual slides
After you have added a comment you can move it around on the slide.
It is possible to add more than one comment box to a slide.
You can easily print the reviewers comments
If you make change to another persons comment then the initial is changed and you become the author of that comment.
Send a presentation for review so that other people can add comments and make any changes they want to their copies of the presentation.
Reviewers can use any version of PowerPoint to review your presentation.
As presentations are completed by reviewers and sent back to you, you can compare and combine them with your original copy of the presentation, and then you can use the reviewing tools in PowerPoint to apply reviewer changes.
When you send a presentation as a shared attachment in an e-mail message, you can create a Document Workspace (Document Workspace:
A Microsoft Windows SharePoint Services site that is created for collaborating on one or more documents.), a Microsoft Windows® SharePoint™ Services Web site that offers one-stop shopping for document collaboration.
People on the To line in your message automatically become workspace members. You can work in your local copy of the file and then use the Shared Workspace task pane to update the workspace copy so all members can always access the most recent version.
For information on sending a shared attachment or creating a document workspace, see the Help topic, Create a Document Workspace.