This article will go through the steps of adding a wildcard mapping in IIS 6.0.
1) Open up IIS, under Web Sites folder right click on your site name and select 'Properties' to get this window:
2) Next go to 'Home Directory' tab and click on 'Configuration' button to bring:
3) Find and double click on any item
that contains a path to aspnet_isapi.dll:
4) In the 'Executable' textbox, copy the text path to your clipboard and cancel this dialog.
5) Now click on the 'Insert...' button. Paste from the clipboard to the textbox.
6) Uncheck 'verfiy that file exists'.
Click 'OK' on all remaining windows and you're done.