Like for IIS 6, in IIS 7 the first step is to create a new Application Pool.
Assign a name to your pool and select the No Managed Code option.
After creating the Pool open the Advanced Settings dialog and make the following modifications:
•Set Enabled 32-Bit Applications to True. (This option is available in 64-bit versions of Windows)
•Set Disable Overlapped Recycle to True.
•Set Regular Time Interval to 0
Now add a new Application.
Note: You can add a new Application to either the "Default Web Site" or to any other existing "Web Site".
Give it a proper name and adjust the Physical path. It is the path where your DLL ISAPI module is deployed.
Select Manage Application and open the Advanced Settings dialog.
In the Advanced Settings property editor set the Application Pool to the one you created in the first step.
The next step is to adjust the handler mapping for the application you just created.
In the Handler Mappings screen right-click on ISAPI-dll and select Edit Feature Permissions.
Check the Execute option and press OK.
If you don't see ISAPI-dll in the handlers list, then you must make sure that ISAPI Extensions are installed in Windows Features. Visit Windows Features to check if it is installed.
The next step is to check the Authentication settings:
Make sure Anonymous Authentication is enabled and the default user IUSR is set.
The last step is to set the security for the web application physical folder. If IUSR is not available in the top list you must add it manually to the list. IUSR is a built-in Windows user account which is available by default. You also need to apply the same access rights to the IIS_IUSRS user group.
Also refer to Adjusting Paths for more information.