How to use Wifi?

I bought this device:
http://www.tp-link.com/en/products/details/?model=TL-WN321G#spec
I install the driver and it start working but it only show one signal and also say unsecured connection and poor quality.
my friend said I have to enter the password of my DSL router but I am not sure how to enter the password and make it a secure connection. I use a password for all other devices (ipad and android) in my computer but not sure how to add it in windows 7.
would be very thankful if someone can help
Answer #1
You should have got a security number (password) with your router …. in the letter perhaps. Normally all you’d do then is click on the network icon (bottom right) in your system tray and when you click on your connection it should show a box for entering the number. You might have to press a wifi button on the router before doing this, so read the instructions.
Answer #2
Y2jEDGE replied:
I install the driver and it start working but it only show one signal and also say unsecured connection and poor quality.
my friend said I have to enter the password of my DSL router but I am not sure how to enter the password and make it a secure connection. I use a password for all other devices (ipad and android) in my computer but not sure how to add it in windows 7.
I got a feeling you picked your neighbors wireless network and not your own,Pay attention to the network name.