Rollercoaster Tycoon Deluxe

Okay. I have had Rollercoaster Tycoon Deluxe for a couple of months. It worked fine. Then all of a sudden it won't run. Stupid error message: Error...unknown location...something to that effect. So I thought I uninstalled it...then tried to re-install it. No luck. Yet another stupid error message: data error (cylic redundancy check) . So I restart, delete program file that the game was located in. Still getting error. How do I completely unistall, then re-install, then download correct patch if needed? Not to sound like a complete idiot...but detailed instructions would be very greatly appreciated. Thanks.