My computer says that it's connected to the internet, but won't let me...

[Cupcakeseee]

...actually get on? Help!? So, its been this way for months now.. It's a laptop, Acer brand, Windows Vista, and it tells me that the internet is connected, but when I click on internet explorer (or any shortcut that would lead to the internet) it says the dreaded "Cannot display this webpage" message. Also, iTunes works! Which makes no sense to me. I've contacted the help hotline or whatever, but they couldn't help me. I know about the DNS server, and nothing related to that seems to be fixing the problem. Is my computer just broken?
P.S. When I run diagnostics it either tells me that there is no problem or that there is a problem that cannot be fixed automatically.

 

[Jockly]

Try a wired connection first directly to the modem or router and see if that works, also try a different browser like Firefox.