I set up router without a password and now I want to protect my data stream with a password access.

First you need to access the router's management screen, typically using the IP address http://192.168.0.1 (type this into your browser while on your network). If the default user ID and password to access the management screens have not been changed they should both be set to "admin". Log in using the admin user ID and password, and from there you should be able to access the router's configuration screens: go to "wireless security mode" in the "wireless settings" screen to set your system ID and access password - I suggest you set a WPA-2 password which all authorized users will need to know.

First you need to access the router's management screen, typically using the IP address http://192.168.0.1 (type this into your browser while on your network). If the default user ID and password to access the management screens have not been changed they should both be set to "admin". Log in using the admin user ID and password, and from there you should be able to access the router's configuration screens: go to "wireless security mode" in the "wireless settings" screen to set your system ID and access password - I suggest you set a WPA-2 password which all authorized users will need to know.

But I don't know my WPA-2 password also,what should I do?