Can't connect to Network even though it had been for ages!

I'm having a similar problem except that my Xbox was connecting to my network fine until we had a short power outage, now I can't get it to connect to my network. It says that the password is incorrect even though it is not.

I can't even get the update to start, even though my network connection is fine

Yah, it doesn't even see the network

Mac Address Filtering is not enabled. I had used that in the past, but

I can see neighbors' networks though can't even try connecting to those since they are all password protected. See what I mean? It's just defying any sort of logic at this point

I can't even open into a game or even YouTube. I run network tests and the wifi is connected so even though xbox live isnt, youtube should still work

I have the same issue... Even though the servers named Europe actually work, I just exclude them from the search! When you can't connect it takes ages, so annoying.