Generally speaking, an add-in is supplemental functionality that adds custom commands and specialized features to the 2007 Microsoft Office system programs. Examples of add-ins are: COM add-ins (COM add-in: A supplemental program that extends the capabilities of a Microsoft Office program by adding custom commands and specialized features. COM add-ins can run in one or more Office programs. COM add-ins use the file name extension .dll or .exe.), automation add-ins, application add-ins (.wll, .xll, .xlam), XML expansion packs, XML style sheets, smart tags, and so forth. This article describes how to view and manage the add-ins for your Office programs.

Excel
Click the Microsoft Office Button , click Excel Options, and then click Add-Ins.
View the add-ins and application extensions that are categorized as follows:
Active Application Add-ins Lists the extensions that are registered and currently running in your Office program.
Inactive Application Add-ins Lists the add-ins that are present on your computer but are not currently loaded. For example, smart tags or XML Schemas are active only when the document that references them is open. Another example is the COM add-ins that are listed in the COM Add-ins dialog box. If the check box for a COM add-in is selected, the add-in is active. If the check box for a COM add-in is cleared, the add-in is inactive. To learn how to open the COM Add-in dialog box, see the section called Manage the installed add-ins.
Document Related Add-ins Lists template files that are referenced by currently open documents.
Disabled Application Add-ins Lists add-ins that were automatically disabled because they are causing Office programs to crash.

Outlook
On the Tools menu, click Trust Center, and then click Add-ins.
View the add-ins and application extensions that are categorized as follows:
Active Application Add-ins Lists the extensions that are registered and currently running in your Office program.
Inactive Application Add-ins Lists the add-ins that are present on your computer but are not currently loaded. For example, smart tags or XML Schemas are active only when the document that references them is open. Another example is the COM add-ins that are listed in the COM Add-ins dialog box. If the check box for a COM add-in is selected, the add-in is active. If the check box for a COM add-in is cleared, the add-in is inactive. To learn how to open the COM Add-in dialog box, see the section called Manage the installed add-ins.
Document Related Add-ins Lists template files that are referenced by currently open documents.
Disabled Application Add-ins Lists add-ins that were automatically disabled because they are causing Office programs to crash.

PowerPoint
Click the Microsoft Office Button , click PowerPoint Options, and then click Add-Ins.
View the add-ins and application extensions that are categorized as follows:
Active Application Add-ins Lists the extensions that are registered and currently running in your Office program.
Inactive Application Add-ins Lists the add-ins that are present on your computer but are not currently loaded. For example, smart tags or XML Schemas are active only when the document that references them is open. Another example is the COM add-ins that are listed in the COM Add-ins dialog box. If the check box for a COM add-in is selected, the add-in is active. If the check box for a COM add-in is cleared, the add-in is inactive. To learn how to open the COM Add-in dialog box, see the section called Manage the installed add-ins.
Document Related Add-ins Lists template files that are referenced by currently open documents.
Disabled Application Add-ins Lists add-ins that were automatically disabled because they are causing Office programs to crash.

Word
Click the Microsoft Office Button , click Word Options, and then click Add-Ins.
View the add-ins and application extensions that are categorized as follows:
Active Application Add-ins Lists the extensions that are registered and currently running in your Office program.
Inactive Application Add-ins Lists the add-ins that are present on your computer but are not currently loaded. For example, smart tags or XML Schemas are active only when the document that references them is open. Another example is the COM add-ins that are listed in the COM Add-ins dialog box. If the check box for a COM add-in is selected, the add-in is active. If the check box for a COM add-in is cleared, the add-in is inactive. To learn how to open the COM Add-in dialog box, see the section called Manage the installed add-ins.
Document Related Add-ins Lists template files that are referenced by currently open documents.
Disabled Application Add-ins Lists add-ins that were automatically disabled because they are causing Office programs to crash.