What security protocol are you using on your WiFi router?
It should be wpa2 personal / tkip+aes
Also check the wireless mode matches your stick eg b, a, n - or put in mixed mode.
DHCP must also be available on the router.
These are the default these days but perhaps for some reason they’ve been changed on your router
If you have other things attached to your network you can also check how they are configured.