How to temporarily disable or remove Slidewise from PowerPoint

To temporarily disable Slidewise in PowerPoint do the following:

1. Click the File menu, and then click Options in the bottom left of the screen and navigate to the Add-ins section.
   
   
2. In the View and manage Microsoft Add-ins dialog check that COM Add-ins is selected in the dropdown and click Go...
   
   
   
   
3. Uncheck the box alongside Slidewise, click OK.
   
   

If you need to fully remove Slidewise for good then you need to read how to uninstall Slidewise.