Home SP2 - Clean Install On Computer

Put a clean install on a computer and it runs great. Only one problem. Some pages when they open do not cover the whole scree like they should. This is hard to explain. When you open the internet the screen is as wide as if should be but what you bring up on the page covers about 2/3s of the page from the middle out. it leaves a couple of inches on both sides. It shows the scroll bars and all its the picture that comes up. If you click on the zoom and make it like 125% it is just right but how can you keep it there? Everytime you change pages you have to use the zoom again if it is the same way, not all pages are like that, but some are