Use the ISAPI Filters feature page to manage a list of .dll files that change or enhance the functionality provided by IIS. For example, an ISAPI filter can control which files are mapped to a URL, modify the response sent by the server, or perform other actions to modify the behavior of the server.
ISAPI filters and extensions are being replaced by the new IIS modules API. For more information about the IIS modules API, see
Sort the list by clicking one of the feature page column headings or select a value from the Group by drop-down list to group similar items.
UI Element List
The following tables describe the UI elements that are available on the feature page and in the Actions pane.
Feature Page Elements
Displays the name of the ISAPI filter.
Displays the path of the ISAPI filter .dll file, for example,
Displays whether the item is local or inherited. Local items are read from the current configuration file, and inherited items are read from a parent configuration file.
Actions Pane Elements
Opens the Add ISAPI Filter dialog box in which you can add an ISAPI filter.
Opens the Edit ISAPI Filter dialog box in which you can edit the selected ISAPI filter.
Enables the Name field of the selected ISAPI Filter so you can rename it.
Removes the item that is selected from the list on the feature page.
Revert to Inherited
Reverts the feature to inherit settings from the parent configuration. This deletes local configuration settings, including items from the list, for this feature. This action is not available at the server level.
View Ordered List
Displays the list in order of configuration. When you select the ordered list format, you can only move items up and down in the list. Other actions in the Actions pane do not appear until you select the unordered list format.
Moves a selected item up in the list. This action is available only when viewing items in the ordered list format.
Moves a selected item down in the list. This action is available only when viewing items in the ordered list format.
View Unordered List
Displays the list in an unordered format. When you select the unordered list format, you can sort and group items in the list, and perform actions in the Actions pane.