Tell us the game. And I might as well give you some instructions. Flash stores its data in a directory which is normally hidden. Anyway, enter the address below on your computer.
C:\\Documents and Settings\\XXXX\\Application Data\\Macromedia\\Flash Player\\#SharedObjects
Replace the XXXX's with your profile's username. You'll then see a strangely named folder, or maybe two. Go through all of them and find the folder entitled armorgames.com. Enter it and you should see some sub-folders, enter them and eventually you'll find folders named after games whose data has been stored. Find the folder of the game you desire, and delete it. Done.
