How do I fix my wireless connection?

[Leeta]

EA6400 Linksys router was working since Friday but I have not been able to get it working again since. When I run the troubleshooter it says: The connection between your access point router, or cable modem and the internet is broken. The network gateway is accessible, but Windows couldn't receive network traffic form the internet.

I have tried system restore to an earlier point because that worked one time before because of an incompatibility with a Windows update.
-I tried rebooting the router.
-Rebooting the modem.
-Made sure automatic IP addresses and all other appropriate boxes are checked.
-Disconnecting and reconnecting to network
-Network troubleshooter in which it says the broadband modem is experiencing connectivity issues which I don't believe because I'm using it manually now.
-All connections are secure and in the right place
-Wi-fi button is on
-Restoring router to default

Just bought router about two weeks ago.

How can I fix the router to work wirelessly again?