If you have change the IP address that an IIS website is pointing to, then find that when you try to restart IIS services you get the error:
The network location cannot be reached.
...you may need to use a utility called httpcfg to tell IIS to listen specifically to the new IP.
To see what IP IIS is listening on, type this in a command prompt:
httpcfg query iplisten
Tell IIS to listen on a new IP address by
httpcfg set iplisten -i [ip address]
To install httpcfg, you may need to download and run Windows Support tools as described here:
It may be enough to restart the application pool and the website, but you may have to reboot the server to get the change to take effect.