yes, install WAMP first, then install the php4 addin. then when you start WAMP server, there will be an icon in the desktop bar on the lower right of your screen. click on that, and select the option 'Switch to php 4". You will see a few settings change, and then php4 will be working. to verify you have php4 running, go to the main WAMP page (http://localhost) and hten click on phpinfo. At the very top it will dispaly the version of php currencly running.