Go to Device Manager and look at the Network Adapters entry. If there's either ! or ? there, you need to get the proper driver. Also click the little arrow to the left so you can see both the LAN adapter and the Wireless one. Right-click the wireless one and click Properties. In the center of the display look for "The device is working properly"inside the Device Status box. If it's not there, you don't have the right driver.
I installed Window 7 Pro on my laptop, and for some strange reason it no longer connects to my Wi-Fi even 'though I have the exact password for it, which works with my desktop. Help!