|I'm not familiar with that unit so I can't say whether or not there's a physical on/off switch for the wireless interface. But, on many other laptops there is, so I suggest you first look for one of those.|
If there isn't one, you need to check the NIC in Device Manager. To get there go to:
Control Panel >> System >> Hardware tab >> Device Manager
Is there an exclamation mark beside the wireless NIC. If not, then something else is wrong. If there is, you may need to unistall, then reinstall it. I would try looking for updated drivers as well.