With so few details to go on, my initial thought is that somehow or another you lowered the resolution on the laptop. Maybe at one point you tried reinstalling the OS and didn't install any video drivers or something else happened. Regardless, I would start by figuring out the maximum (or native) resolution of your laptop's display and make sure that it matches what you see in the display resolution properties. If they match, odds are your computer is simply too old and there will be no easy solutions to the problem because the issue is that web developers are now making assumptions about computers which do not hold true for you.