The wireless WLAN card is the hardware component of a Dell laptop computer (for example) which lets you connect to a wireless router and access the home network or internet. The Dell wireless WLAN hardware card supervises, locates and provides information about wireless networks available in your area. It allows you to diagnose network problems, create network profiles and connect to an existing network. Dell provides this wireless configuration utility packaged with the drivers for wireless WLAN cards installed in your laptop. Your Dell laptop computer wireless WLAN card may stop working because you are not running the latest drivers. It could also be because of your laptop computer getting overheated along potentially with your motherboard.
I'm using a Dell 1520 and each time I boot it, I'm getting an error message saying the "WLAN card wireless network controller stopped working and was closed".
I had the same problem with my Dell XPS. Chances are you computer has the same problem. If you haven't fixed it yet I have some solutions for you.
1. You're not running the latest drivers (easy installation).
2. It may not be your WLAN Card at all. It could be that your laptop is overheating and your computer responds to save your motherboard from overheating. Your card might just stop working because of this.
Where is your laptop located? On a desk or some sort of flat surface?
Do you have a fan running underneath it?