Do you have the right aspect ratio set for the 360? The old TV's are 4:3, not 16:9. If you do and the game still doesn't fit, you might be out of luck. A lot of the newer games don't support 480p that well. It's probably time for a new TV. Depending on how old your TV is, there might be a screen adjustment setting built in to the TV menu. Sometimes you can actually move the screen around to fit the corners of your television, but most just have presets such as wide, full, etc. that you can select. Something like "Full" would probably work the best, but you can play with it a bit.