"Connected" but can't get online in Windows 7

I just upgraded to Windows 7 when I installed a new (64-bit) motherboard and processor. I access the internet through a Linksys router and while my computer shows I am "connected", I still can't get on either Firefox or Explorer (64-bit). The windows will open but I get the message "Server not found." I've walked through the process of allowing the two websites to run through the firewall that comes in Windows 7 but that hasn't helped me get online. It's so frustrating to see my connection bars showing green (connected) at the bottom of my screen but remain unable to access anything online. And the evn weirder part of this is the first night, I spent hours trying to figure this out and at some point, I did get online for about an hour. Unfortunately after shutting down and starting up the next morning, the magic was lost.

Could it be that the router is too old / not 64-bit compatible? And if so, why did I get online that first night? It isn't software specific because I can't get Outlook to pull in email either. Anyone have an idea or thoughts about my old router?