Jocelyn,
You need to go to your project page via the Customer Portal (link at the top of the site) and grab the license key there. Then, paste that into the Wwise License Manager (Ctrl-L in Wwise). That'll open up the project to go beyond the 200 sound file limit. Seems you've been in evaluation mode this whole time!
Mike Drummelsmith (@AKMikeD) - Director, Developer Relations