Problem loading webpages/ but comes up after hitting refresh one or more times

I have a new Dim 9200 and every time i open my web browser (same with explorer and firefox), half of my tabs state that they have problem loading page. But all I have to do is press refresh several times and it comes up. I think it is something to do with my computer. I had to reboot the entire system and reinstall windows because there was a bug in it. I am just wondering if I failed to install something properly.