Can not connect to anything but a game.

[Buco]

I recently moved and went with Comcast Internet. Never had a problem before with my previous provider.

After about a month, my desktop pc couldn't connect to the Internet. Wifi was working fine though. iTunes, IE, Firefox, and anything else couldn't connect. The only thing that can is the game World of tanks. But it can't connect to the update server, so as long as there isn't an update, I can play it online.

Had 2 techs come out, switched modems and it still won't connect. Tried hooking it up through a wifi device and nothing. They say it is my pc. I took it to staples for their free pc check up and I could connect to the Internet there with no problems.

Any idea what could be the problem and how I can fix it? I go into network settings and everything looks like it should be connecting fine, but it can't.