I'm getting 404 error messages when I try to run any .aspx files on my server (W2K8, joined to ADS domain). .html files run just fine from the same directory. I believe this is caused by lack of permissions to the DefaultAppPool to the directory where I am trying to run .aspx.
In IIS 6, you could easily see the IUSR account in Users. What do we do in IIS 7? How do I get rid of the 404 messages when I try to run.aspx files ?