If at all possible try to convince the client to let you run WAMP. I had to manage an IIS EE site for 3 years and it was an absolute nightmare.
Make sure you have .php set as a default document and higher priority than .html.
You may want to purchase ISAPI_Rewrite, which would allow you to use an .htaccess for any URL rewriting.
Permissions are a nightmare. ...
If that page has been added to the Pages module list, it will require a URI. And if you've left at least one other blank, then that's where your duplicate URI is coming in. Just check out the Pages module list and make sure you delete the page from there -- it won't actually remove the page entry in the channel though.
What do you have in your web.config file? You'll find this in the site's root. Are you using web.config to redirect all requests to your index.php file? If not, this might help:
This became way too problematic and another solution was suggested to the server admins which they accepted. This solution allowed for the more typical ExpressionEngine setup and environment which removed all of these problematic issues.
For anyone who runs into this, I resolved it by modifying the web.config file to allow errors to "PassThrough".
I changed the following:
<httpErrors errorMode="Custom" existingResponse="Replace">
<httpErrors errorMode="Custom" existingResponse="PassThrough">
This resolved the issue I was facing. However, I wil only turn this on when I ...