But when you click Apply you get the response: Reserving url http://+:80 The Url has already been reserved

RESOLUTION:  Using the "netsh http show urlacl" command we see that /ReportServer and  /Reports are already reserved. You can also run "netsh http show urlacl | find "Report"" - to see just those two lines. >netsh http show urlacl | find "Report"     Reserved URL            : http://+:80/ReportServer/     Reserved URL            : http://+:80/Reports/

To resolve - simply delete the reserved URLs and recreate them.  I think we're to assume SRSS had been installed on this server once before but not properly uninstalled.

C:\Windows\system32>netsh http delete urlacl http://+:80/ReportServer/ URL reservation successfully deleted

C:\Windows\system32>netsh http delete urlacl http://+:80/Reports/ URL reservation successfully deleted

Then if you re-run >netsh http show urlacl | find "Report" - you'll see nothing.

Now to re-create the bindings:

1. Open "Reporting Services Configuration Manager" -Click Connect
2. Click "Web Service URL" - then click "Apply" at the bottom and it should succeed this time.
3. Click "Report Manager URL" - then click "Apply".  If Apply is grayed out, simply rename Reports to Report, then back to Reports.  Apply will become available and you can click it.
4. Then visit each URL to test.