Hello...
1) my N800 wireless can connect my home web key internet.
2) I going outside, public hotspot wireless can not connect all the time. say "network error". my laptop can connect.
how can I fix this problem.
Please help me.

You'll have to give a little more info. We're not mind readers here.

I will attempt to read your mind.

The N800 sees the networks, however, the wireless network may have MAC address restrictions in place. I believe that can generate the error message you are seeing. I believe a network with MAC restrictions still appears as unlocked on the network selection screen because none of the 802.11 encryption methods are in use.

If you haven't purchased an account with them then they don't let you on their network! So unless you have signed up and given them your MAC address then they won't let you play... Other possible reasons - the router is fully in use and cannot issue you an IP, or as I have found external WiFi is pretty crap and never strong enough to give you a stable signal!