Hi
1.- Go to control panel, network and sharing center, and then on youir left press Manage wireless networks,then on the open window youll see the option Manage wireless networks that use
Below youll see Networks you can view,modify and reorder,
select all of them and one by one remove them.
2.- On the right hand near the time, press on the computer icon and then you will see the networks near you, find your network, click on it and connect, add your security key and then connect, be sure that the on/off button wireless option is on the mode on,
If that doesnt work, let me know, and i will try to give you further assistance....
Let me know if i helped u, ok? it worked to me!!!