Need more details, did it work before? What happened to it after it stopped working if it worked?
What exactly do you do to try to connect and exactly what happens, need error messages, etc...
Do other wireless devices connect to the router?
I bought it one month before and it always connected to my wifi right at one month. Wouldn't connect to any wifi, hotspot of friends house. No error message. Just kept saying "connecting" endlessly. All other devices in my house were connected. After trying every solution I saw, including looking in the BIOS setting but nothing worked.
I began to suspect think the end of my free McAfee trial had been about a week ago, around same time it stopped connecting. Took over a half hour for my computer to uninstall McAfee. When it restarted it immediately connected.