About add-in programs

Where to get add-ins    A set of add-ins is available when you install Excel, and more add-ins are available from the Microsoft Office Web site.

Installing add-ins on your computer    Before you can use an add-in, you must first install it on your computer and then load it into Excel. Add-ins (*.xla files) are installed by default in one of the following places:

• The Library folder or one of its subfolders in the Microsoft Office/Office folder.

• The Documents and Settings/<user name>/Application Data/Microsoft/AddIns folder.

The administrator for your company's network can designate other locations for add-in programs. See your administrator for more information.

Loading add-ins into Excel    After installing an add-in, you must load it into Excel. Loading an add-in makes the feature available in Excel and adds any associated commands to the appropriate menus.

Unloading add-ins from Excel    To conserve memory and improve performance, unload add-ins you don't use often. Unloading an add-in removes its features and commands from Excel, but the add-in program remains on your computer so you can easily reload it. When you unload an add-in program, it remains in memory until you restart Excel.

Designing custom Excel add-ins    You can use your own Visual Basic programs as custom add-ins. For information about making a Visual Basic program an add-in, see the Microsoft Office XP Developer's Guide, which you can obtain from Microsoft.

COM add-ins are supplemental programs that provide additional functionality in a variety of programming languages, including Visual Basic, Visual C++, and Visual J++.

Using COM add-ins    The developer of a COM add-in usually provides installation and removal programs for the add-in. Contact the person who provided the add-in to you for instructions on how to install and use it.

Designing COM add-ins    If you are a developer, you'll find information about designing COM add-ins in Visual Basic Help. While you are developing and testing, you can load or unload a COM add-in in Excel before you have a working installation program for your add-in.

Automation add-ins allow COM automation functions to be called from a worksheet.

Using automation add-ins The developer of an automation add-in usually provides installation and removal programs for the add-in. Contact the person who provided the add-in to you for instructions on how to install and use it. Automation add-ins that have been registered on the system can be accessed through the Tools menu.