Pages online wont load.. please help...

Hello, everyone
How is everyone tonight i need help and i hope one of you guys can help me solve my problem.. When i use my desktop there are certain websites that wont load it said that the page is not available.. I noticed that the majority are website that i need to log in like myspace, online banking, etc etc.. it only happens with my desktop i can log in to those pages on my laptop. A friend and the company i got my router from keep telling me that there a firewall that's blocking those pages but i've tried disabling my firewall and still. My friend said that he will reboot my computer but i dont want him to do that cause it runs fine.. thats my only problem please is there someone one out there with an answer that can solve my problem if so thank you very much..