Installing ISAPI Filters

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1

You can install filters for all of the sites on an application server (global filters), and you can install filters for individual Web sites (site filters). If you install both global filters and site filters, the two filter lists are merged for the site.

When several filters have registered for the same event, they are called sequentially. Filters with a higher priority are run before filters with a lower priority. If several filters have the same priority, global filters that are set in the master properties are run before the filters that are set at the site level. Filters with the same priority at the same inheritance level are run in the order in which they were loaded. You can change the filter load order by adjusting the properties for the Web server or the Web site.

Procedures

Important

You must be a member of the Administrators group on the local computer to perform the following procedure or procedures. As a security best practice, log on to your computer by using an account that is not in the Administrators group, and then use the runas command to run IIS Manager as an administrator. At a command prompt, type runas /user:Administrative_AccountName "mmc %systemroot%\system32\inetsrv\iis.msc".

To add a filter to a Web server or Web site

1. In IIS Manager, expand the local computer, right-click the Web server or Web site to which you want to add a filter, and then click Properties.

2. Click the ISAPI Filters tab, and then click Add.

   Note

   If you are adding filters to a Web site, you will not see any global filters inherited from the Web server's master properties. You will see only the filters installed for the Web site, even though both sets of filters are run.

3. In the Filter name text box, type the name of the filter.

4. In the Executable text box, type the name of the DLL file or click Browse to navigate to it, and then click OK.

5. Click the up or down arrow to change the load order of a filter.

   Note

   You can only change the load order of filters that have the same priority.

6. If you have added or changed a global filter, you must stop and restart the Web server to load the new filters into memory.

Related Information

• For information about checking the status of ISAPI filters, see Checking ISAPI Filter Status.

• For information about how to fine-tune server performance by caching ISAPI extensions, see Configuring ISAPI Extensions.

• For more information about ISAPI filters, see ISAPI Reference in the IIS Software Development Kit (SDK).