how do i un lock wireless on packard bell windows xp?

i dont have a manual for my packard bell windows xp i am trying to connect to wireless i dont have a switch on my laptop wen i connect it stops connection and error with sidebar appears on the screen.my laptop is about 5 years old and is the first time i have tried to connect to wireless.please help anyone i am new to computers.e-mail me with any suggestions at kate.mf@hotmail.co.uk