WAMPSERVER can not access from url localhost but 127.0.0.1 is ok ( on win8 )

I just switch to win 8 from win 7. On win7 everything is OK with wampserver, but

When i try to access my wampserver via url localhost on win8, i got this error

Forbidden

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

but via url 127.0.0.1 is OK.

I try fix that error by change in phpmyadmin.conf into

<Directory "c:/wamp/apps/phpmyadmin3.4.9/">
    Options Indexes FollowSymLinks MultiViews
    AllowOverride all
        Order Deny,Allow        
    Allow from all  
</Directory>

Could anyone help me fix this error? Thanks!