Dell inspiron n5010 - screen resolution is big i.e 1024 x 768

Hi, i have a dell inspiron n5010, windows7 ultimate. I've just formatted my disk, and having screen resolution problem. it's 1024 x 768, which is huge and unclear. I've tried to uninstall all drivers and install again, but it is still the same. I even downloaded all drivers from dell.com, but still the same. please guide me what to do further. thanks.