If you want to get a quick summary of all of the add-ins installed for your MS Office applications (Word, Excel, Outlook, PowerPoint, et al.) use NirSoft's OfficeIns, an Office add-ins manager available for download here.

OfficeIns downloads in a zip file. It's a stand alone executable file - no installation necessary.

It will automatically generate a list of all add-ins and their current status.

Best of all you can right click on any one add-in and change whether it loads at startup or is disabled. A great way to troubleshoot performance issues with your MS Office applications.