Macbook receiving internet signal but not actually working

I've been googling this entire day trying to get the wireless internet on my macbook to work. I have a Netgear WPN824 router that I just bought yesterday and it works fine on my other PC and laptop, just not on my mac. I've been reading that people have been having trouble getting internet through their macs with a netgear router. However, no one has been able to find a solution for it. I can connect my MacBook to my Netgear WGT624 router without WPA security enabled but I would like to use WPA2 to secure it, but whenever I turn these features on, the computer connects to the network (with full bars), but cannot access the Internet. I keep getting an "Address Not Found".

I was able to get internet earlier, but everytime I close my laptop and start it back up, and I attempt to go online, it displays the "Address Not Found" page again. I've had to go to System Preferences and mess around with it for it to work.

Someone told me that if any of my proxies were checked off on my "Network," then I should uncheck them, which did make my internet work. After I closed it and reopened it 20 minutes later, the error page displayed again even though I had all bars.

I did both of them and neither worked. I'm still getting the "Address Not Found"

I did a software update last night and still nothing.
Andris, did you mean a router software check or a mac software check? Because I've done both and still not getting any internet.

I wasn't too positive what my dns servers were, so I googled them (btw I'm with comcast). But even after I put them in, I still didn't get any internet. Whenever I opened firefox, it would take a looong time to load, but in the end, it would still display "Address Not Found".

By the way, is there supposed to be an IP address next to "Router:"? If so, that might be the problem because mine is blank. How do I go about fixing that?
Here are some print screens, to make it easier to understand:

Oh, yes I completely updated my mac yesterday but still can't get internet.

Andris, my AirPort has gone green before, but even when I clicked on Firefox, the "Address Not Found" page still displayed.

And how do I go about finding my subnet mask? I don't know how to do that on Windows either, sorry. I'm pretty computer-illiterate.

I actually posted this problem on another forum and they were able to figure out. Finally my internet is working. Thanks to everyone who attempted to help me here, much appreciated!