Laptop lost wireless connection suddenly

Hey guys, my wife is having a strange problem with her laptop and I can't figure it out.

She said she was on the internet, and suddenly the connection stopped working. Ever since that moment she seems unable to connect to our wireless network. We fiddled with the settings of the router and changed the laptop's settings accordingly, but it still wouldn't connect. But the windows connection troubleshoot seems to say the problem is coming from the router, if I keep pressing next it mentions: wireless adapter or the wireless adapter's connecting point. But the wired connection to my main PC seems to work fine.

The router was handed out by my ISP: Shaw. It's a Cisco, don't know the model number. The router is pretty new, they sent it to me when I upgraded to 50+Mb/s broadband internet. The laptop is a Samsung RC-510. It is fairly new, bought it 2 months ago.

I am pretty good with hardware, but when it comes to networking I know very little. Can someone help me out with some suggestions?