IIS 7 doesn't change the way that links are referred. In fact that's not one of a server's tasks, but it's the browser that needs to fix up the URL and send it to the server as a complete URL. Browser reads the HTML and HTML Link and fixes up any relative paths into full path urls that the server responds to - a Web server has no notion of last request and therefore no idea about relative paths - it only responds to full URL endpoint requests.
So I'm not sure I understand what problem you have here. Maybe you need to be more specific and show an example of what doesn't work.
+++ Rick ---
from Maui, Hawaii