Help! Wifi won't connect what so ever!

I bought my Alienware three months ago, and today it suddenly stopped connecting to the internet. I have an M14x. The connection says "No connections are available", but the wifi on my desktop is working perfectly. I've been searching these forums and many other's today for hours. So far no results! Could someone please give me a hand? I have an important video meeting later today and I need to have it on that laptop!