Today I had the need, to be able to turn the wireless adapter in a tablet on and off, and be able to connect to a known wireless network, from a script. I wasn't fussy, either a batch file or powershell script would work.
The rather simple solution, was found over at http://www.hanselman.com/ in his blog post How to connect to a Wireless WIFI Network from the Command line in Windows 7
Credit to Scott Hanselman
The NetSh commands work well in this instance.
Disconnect the wireless adapter from the wireless network:
netsh wlan disconnect
Connect to a known wireless network
netsh wlan connect name=<WIFI NAME>
Show all wireless networks
netsh wlan show profile
For Powershell versions of the command, check out Scripting Guys Posts; Hey Scripting Guy