"No internet games responded to the query"/Other irritating issues.

[CAL]

I've had this problem for around 2-3 days, and I'm beyond fed up with it. I log into TF2 and click on the 'Servers' button on the main screen, and it either brings up a "No internet games responded to the query" or a neverending refresh of the server list. Nothing shows up, other than the "Internet query" error on occasion. I've tried to get around it any way I can: Using the View Servers option in the user interface, attempting to join my friend's servers (Comes up with Error - Server is not responding), and even the connect command in the console. None have worked.

I'm guessing this is a problem on my end, maybe a firewall or a faulty router/modem setup. My antivirus is WSE (Windows Security Essentials) and my firewall is Windows Firewall.

I've looked around for answers, and literally have tried everything: uninstalling/reinstalling Steam, deleting the .vdf files (only found one, and deleting it only seemed to make my game worse) and the .blob file (couldn't find it at all), wiping my TF2, verifying my cache after wiping it, resetting my modem, uninstalling things I thought might have blocked my connection.

I need this fixed. Anyone that could offer help would be more than appreciated.