WAMP server will not access localhost but will respond to 127.0.0.1

My laptop has WAMP server installed.  Just recently when I type localhost into the address bar, I get

Forbidden

You don't have permission to access / on this server.

If I type in 127.0.0.1 I get the expected result.  This confirms WAMP server is running.  The icon is green.
Skype is not instaled and never has been.

Based on mr google, I check
C:\Windows\System32\drivers\etcC:\Windows\System32\drivers\etc\lmhosts.sam
There were no entries in it.
I added
127.0.0.1        localhost
To save the file, I had to change the permissions.  Right click>properties.
Rebooted.  Made no difference.

http://serverfault.com/questions/266045/localhost-on-wamp-returns-404-changing-port-numbers-doesnt-help
2) A 404 error is not caused by firewalls. 404 HTTP status code means that the server (Apache) received the request but can't find the asked for file (bad url or missing file).
A firewall issue would simply block the request and you would get nothing back (no status codes).

Sounds logical.