1. Check your TV manual for instructions on how to adjust the aspect ratio.
2. Make sure your display settings are set for 4:3 or 16:9.
3. Look for a zoom button on the remote or on the TV itself, and press it to adjust the picture size.
4. Adjust the ratio manually using the control buttons on the remote or on the TV itself.
5. Adjust your cable or satellite box settings, and ensure that the aspect ratio settings match those on your TV.