My wireless g usb adapter can not connect to wifi router

[evyda]

I am a newbie. I just changed my wifi modem and now I have a problem to connect my wireless g usb adapter on my PC to wifi. This wifi modem has a password. Please help me how to setup the network connection.
Thanks in advance.

 

[nhasian]

How to find or change your wireless security key

If your forgot your router's default username and password you can look it up at:
http://www.routerpasswords.com/