Edit php.ini file
It is easy with a few steps. Left Click wamp server icon -> PHP -> PHP Settings -> You will see all basic settings here. Fore example you can increase "upload_max_file_size". Regards..
Yo can find that in phpinfo()
<?php
phpinfo();
?>
check for Configuration File (php.ini) Path
there in the output.
The wampmanager icon, which sits in the system tray has a menu system.
Use that to edit your php.ini file that is used with Apache.
So its
(left click ) wampmanager icon -> PHP -> php.ini
It could not be simpler.
EDIT/UPDATE:
And now in WAMPServer 3 it has become even easier to change some of the more obvious PHP Settings.
(left click) wampmanager icon -> PHP -> PHP Settings
and you should see a new menu where you can amend some setting from the menu system as below.
If there is a Green Tick by an On/Off option then that parameter is set to On.
If there is a green arrow symbol to the left of an option, that will either open a selectable list OR a dialog where you can enter a value manually to suit yor needs.