Wireless network connection shows up as connected, but no internet

I usually run this tower (Dell XPS 8700, details in specs) with a wired ethernet connection, but may need to run it wirelessly in the near future, so I tested the wireless connection and it doesn't work.

In the networking icon in system tray, I can select my home wireless network and "successfully" connect to it - password requested and accepted and it shows "Connected" next to the name of my wireless network.

But in the Network and Sharing Center, the connection between the home network and the internet shows as disconnected. And I have no internet access. I cannot even login to my router.

If I plug in the ethernet cable, everything is fine - in the Network and Sharing Center, it shows I'm connected to the internet. And I'm able to login to my router, browse the web, etc.

I have other devices (mobile devices and a Windows 7 laptop) that wirelessly connect to the same home wireless network and they can access the internet just fine.

Any ideas on what the issue could be?

Figured it out - sort of.

It's a wireless mode issue. In the router's Wireless settings, the wireless mode was set to Auto, which is the default. I switched it to Legacy, and then my PC's wireless connection works fine.

Interestingly, I switched the wireless mode back to Auto, disconnected the wireless connection and reconnected it. And now the wireless connection works fine. Strange, but at least the connection is working.