Issue setting up on IIS

I’m trying to follow the web.config setup found Bedrock web.config.

When I view the site using localhost/ I get the following error.

403.18 - Forbidden ‘The specified request cannot be processed in the application pool that is configured for this resource on the Web server.’

This is odd as I have 5 other WordPress sites configured and running on this server. They are not using bedrock though.

In the Detailed Error Information I have these two items but they are wrong.
Requested URL: http://localhost:80/web/
Physical Path: D:\Web\Sites\web\

When they should be:
Requested URL: http://localhost:80/site1/web/
Physical Path: D:\Web\Sites\site1\web\