The system tray icon says "offline" on mine too, but it works OK. It may be that that only indicates that I don't have it open to the world, just localhost. If you left-click that icon, there should be an option to restart all services. If you do that, watch the icon to see if the "dial pointer" eventually moves from the left (red) to most of the way to the right (yellow) then all the way (white) when it's done.
If so, you should be good to go. Remember that your PHP scripts will need to be in the "www" directory under the WAMP directory, and you must access those files via a localhost URL in the browser (i.e., you cannot just double-click them from the Windows file explorer).
