wifi connect

i used to connect to my father in-law’s internet. i know his wep key. for some reason i cannot connect now. is there other ways to block people? if so, are there ways around them? using windows vista. thanks.
Answer #1
The way to prevent people from connecting is not to use WEP…Use WPA or WPA2…
Answer #2
its possible that he either a) changed the key or b) added a mac filter
mac filters allow or disalow devices to connect based on their unique adaper identifier code. it is possible to spoof macs, but you would have to figure out the mac of an autherized device and spoof that. if the real device connected, it would cause unpredictable beheviour