|You should have a "wireless profile" for the connection. You would want to delete that profile and then reconnect to the wireless LAN. You would immediately be requested to enter the key.|
I'm not as familiar with Windows 7 as I am XP so I can't tell you where to find the wireless profile manager. Hopefully someone else who does know offhand where to look will post in here and give you directions. In the mean time, you might start by looking through the properties for the wireless network interface.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.