Internet Information Server uses ISAPI filters to monitor HTTP transactions and to authenticate users. Before Internet Information Server can load these filters, they must be added to the W3SVC key in the Registry. After they are added, Internet Information Server loads these ISAPI filters automatically when the WWW service starts.
Û To install an ISAPI filter
1. Copy the filter DLL to an appropriate subdirectory, such as Scripts or Cgi-Bin.
2. Run Regedt32.exe.
3. Add the full path of the filter DLL to this Registry path:
HKEY_LOCAL_MACHINE\System
\CurrentControlSet
\Services
\W3SVC
\Parameters
\Filter DLLs
Note
If there is more than one filter DLL file, separate them with commas. For example:
c:\Inetsrv\Server\Sspifilt.dll,c:\Inetsrv\Scripts\Myfilter.dll
The security precautions you must take for ISAPI Scripts subdirectories are similar to the permissions you have in place for Cgi-Bin subdirectories. Always review who has write permission to the ISAPI Scripts and Cgi-Bin subdirectories.