Hooking your computer up to your TV is a good way to watch videos or look at pictures stored on your computer. Once a TV is connected to your computer and the display moves to the TV, the television acts just like a computer monitor would, so changing the screen size works the same way as on a computer monitor, or when using a projector with your computer. This procedure will change your screen size in Windows Vista and Windows 7.
Connect your computer to your TV so that the display shows up on your television.
Click the "Start" Menu and open the "Control Panel."
Open the "Appearance and Personalization" menu, and click "Adjust Screen Resolution." This will bring up a window with "Display," "Resolution" and "Orientation" options.
Click on the arrow next to "Resolution" and select the resolution your television is designed to display. This information can be found in your TV's owner's manual.
Click "Apply" and then click "Keep" to use the new resolution.
If you've connected your computer to your television, but your computer's display isn't appearing on your TV, you can use the "connect to the projector" option in the "Display" menu. This option will bring up a small bar with several options. "Duplicate" will display your computer screen on both your computer and the TV. "Extend" gives you options to show both displays at once, or alternate between the two. Finally, "Projector Only" will tell your computer to display on only your TV. If you are unable to get your TV to display your computer's screen, try adjusting the resolution of your computer before connecting it to the TV. Some computer resolutions are incompatible with televisions.