Okay, I suck at Roller Coaster Tycoon. I downloaded a lot of parks and rides from the internet, and when I double click the ride icons, Roller Coaster Tycoon comes up and a message like this appears "Ride design already installed." But I checked and checked and could never find the ride design that I downloaded. Can anybody tell me how to build the rides that I got from the net? Do I have to be in a certain scenario? Thanks in advance.