The questions is , is it your own internet service that you are using or someone else.
If you are using someone else wireless serivce then the chances are the person has block you out from using their serivce or router/
Your network card doesn't pick up the signal very well and you will have to buy a network card that can reach limits from 500m to 1200meter/Or you can buy
a wireless router and store it high on a cabinet so you can get better coverage signal. They do help....