Do you have an anti-viral program on your computer? That could be the cause of it. I had a problem like this, and it turns out the problem was with the anti-virus program.
It depends on the type of anti-spyware program. I think what you'll have to do is give the Nintendo Wi-Fi Help Support Hotline a call and schedule a call with a Wi-Fi expert. They'll help you find the problem over the phone.
Here is what the official nintendo wifi site said:
Error Code: 86420
Unable to establish UDP connection to the game server.
Please verify that your UDP settings match the settings on your firewall.
Home:
If this error occurs regularly, while you are playing at home, it is likely a connection problem related to your firewall settings. For more information on firewalls and the Nintendo WFC, click here.
maybe video game world but then again i expirenced some pretty bad support from alot of game companies
my personal fav is HP they have tech chat witch is like a phone conver without the hassel
