PHPBB is a bulletin board (forum) that you can host locally. All your local run websites can be accessed by typing in 127.0.0.1 into your address bar. If you download WAMP, it will give you a SQL service console, and a server console. Its ideal for anyone looking to get started with thses languages and db's. If you decide to get PHPBB, it will ask you how you want to run this (either connect to another server or locally) with the 2nd option being your choice. If you run into problems repost and I'll help you out.
Have you made sure IIS for Windows isn't running. I had the problem with Windows XP that wampserver wouldn't start the services if IIS was running. It doesn't seem to effect Windows 7 though so I assume IIS is not automatically started.