The COM Add-ins menu option is not available by default. You need to add it to the menu bar by using the Customize feature.

1. Select Tools > Customize
2. Click on the Commands tab in the window.
3. From the Categories list select Tools.
4. In the Commands list scroll down to locate COM add-ins.
5. Click & Drag this Command button on to the Tools menu. 
6. Click Close on the Customize Window.

Now you can click on Com add-ins from the Tools pull-down menu.  Click on it and you will see the following window:

Here you can see a list of COM add-ins that are installed.  By highlighting an add-in you can see the location of the file and the load behavior.  If there was a problem loading the add-in there will be a brief description of the problem here.

All add-ins with a check mark in the box are currently loaded.  You can Uncheck an add-in to temporarily disable it (it will remain in this list, so you can easily re-enable it), or remove it completely by highlighting the add-in and clicking on Remove.