Problems adding add-ins
You've created an add-in but it won't install or run on your computer or someone else's.
Or you've downloaded an add-in but can't get it to install.
The usual reason for this type of problem is security settings. If you have your PowerPoint macro security set to High or above, add-ins can't install themselves.
See How to set Macro Security in PowerPoint to learn how to set security to reasonable but still safe levels.
Now try adding the add-in according to the developer's instructions (or use Tools, Add-ins and click Add then browse to the add-in's .PPA file and add it).
Note: after installing an add-in, you can choose Tools, Macro, Security and set it back to High in PowerPoint 97-2003.
If that doesn't help and you're using PowerPoint 2002 or higher, choose Help, About Microsoft Office Powerpoint and click "Disabled Items ..."
If your add-in is listed there, click its name then click "Enable" to re-enable it.