Well you have posted many things you did and haven't posted about the thing I'm going to say, so I'll try to help.
Do you have WEP or WPA security settings configured on the connection settings of the Wii? If not, you need to check. To check what type of security your router takes, go to "Wireless" or "Wireless Security" section on the router settings of your PC. Then when you search for the access point on your Wii, choose the access point, scroll over to the right first to find the "Security" section. Choose the security your router takes.
If that doesn't work, go to the support section of the Nintendo site and there should be an "Error Code Lookup" on the left side.