Not able to log into forums or my email account

Hello, I'm having a strange problem when I'm on the internet. When I try to access a site such as a forum sign-in page or my e-mail account page, my internet explorer browser does not go to the page and instead gives me an error page that states that it can't find the page I'm looking for. I think that this also ties into a strange problem with my world of warcraft game where I can log in, but can't actually play the game. I have a wireless router, A Netgear 624 v2, and I'm not sure if that is the problem or whether it's a problem with some software on my computer. I'm also running Avast Anitivirus Demo edition. Thank you very much for any help that you can give.

 

Do you have XP service pack 2?

 

Yes, I have installed windows service pack 2.

 

Check if the below link helps you:

http://support.microsoft.com/kb/870700