Change the file content of c:\wamp\alias\phpmyadmin.conf to the following.
You should remember to set the Allow Directive to allow it from your local machine for security purposes. The directive Allow from all is insecure and should be limited to your local machine.
<Directory "c:/wamp/apps/phpmyadmin3.4.5/">
Options Indexes FollowSymLinks MultiViews
AllowOverride all
Order Deny,Allow
Allow from all
</Directory>
Here my WAMP installation is in the c:\wamp folder. Change it according to your installation.
Previously, it was like this:
<Directory "c:/wamp/apps/phpmyadmin3.4.5/">
Options Indexes FollowSymLinks MultiViews
AllowOverride all
Order Deny,Allow
Deny from all
Allow from 127.0.0.1
</Directory>
Modern versions of Apache 2.2 and up will look for a IPv6 loopback instead of a IPv4 loopback which is your localhost.
The real problem is that wamp is binding to an IPv6 address. The fix: just add Allow from ::1 - Tiberiu-Ionuț Stan
<Directory "c:/wamp22/apps/phpmyadmin3.5.1/">
Options Indexes FollowSymLinks MultiViews
AllowOverride all
Order Deny,Allow
Deny from all
Allow from localhost 127.0.0.1 ::1
</Directory>
This will allow only the local machine to access local apps for Apache.
Restart your Apache server after making these changes.