how do i adjust the settings on my computer to make what i see on my computer the

[junior_morrow]

same as on my TV? it's hooked through an HDMI cable, and i cannot get them to be exactly the same. when i hook it up, the picture on the TV is a little bit zoomed in and i cannot see the whole desktop. when i first plug it in, i click the button to make the two screens the same, but the TV still shows up a little too zoomed in. anybody help?