Installing ISAPI Filters (IIS 6.0)
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.
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