Hi all,
My findings on this issue were a little different from some of the other posts. I spent some time running down the permissions, but didn't get any farther after making the changes the other contributors described. Here's what I did to make some progress... (assuming XP Pro).
Navigate to IIS >> local computer >> Web Sites >> Default Web Site. Right click and select New >> Virtual Directory. When the wizard opens, click Next. In the Alias text box, enter "www.mysite.com" and click next. Click the browse button and navigate to c:\intepub\wwwroot. Click "make new folder". The folder name will be "www.mysite.com". Click OK. Click Next. Click Next. Click Finish. Create a file called index.htm (put "hello" or something in the file you will recognize) and drop it in the directory C:\inetpub\wwwroot\www.mysite.com. Next, open your browser and type "http://localhost/www.mysite.com in the address bar. Error 403.1 is displayed (or at least it is on my browser.). Now for step 2..... this is where it gets interesting...
Do the same thing again, except name your site "mysite.org" instead of "mysite.com". Follow every step in creating a new site, the only changes being the virtual directory name "www.mysite.org" and wallah, the page is displayed. From the www.mysite.org directory, I can run asp pages, etc, but from the www.mysite.com, nothing runs.
Comments, suggestions are welcome.