what ? you're going to need to explain yourself better than that .. for instance what software you used etc etc.
Are you talking about overscan? Most people mistakenly believe that they are seeing the entire picture on their TV when in reality some of it is cut off. Some TVs cut off more than others, but it's normal. On the other hand, a computer monitor displays the entire picture, and this may explain why it doesn't fit as you expect it to.