Abaixo os passos para alterar a porta padrão do Apache no WAMP de 80 para 81 (fonte):
Open the httpd.conf file for the Apache server. On my machine, it’s located here C:\wamp\bin\apache\apache2.2.8\conf\httpd.conf
Do a search for "Listen 80"and replace it with "Listen 81".
Save and close the file.
Open the wampmanager.tpl file. On my machine, it’s located here: C:\wamp\wampmanager.tpl
Do a search for "http://localhost/" and replace it with "http://localhost:81/" (There are three total).
Do a search for "${w_testPort80}" and replace it with "${w_testPort81}".
Save and close the file.
Open the testPort.php file. On my machine, it’s located here: C:\wamp\scripts\testPort.php
Do a search for "80" and replace it with "81" (There are three total).
Save and close the file.
Open the english.lang file. On my machine, it’s located here: C:\wamp\lang\english.lang
Do a search for “$w_testPort80 = ‘Test Port 80";” and replace it with “$w_testPort81 = "Test Port 81";.
Save and close the file.
Right click on the WampServer icon and click on “Exit”.
Restart your WampServer.
