Installing Wireless ipw3945 drivers in Debian

1. Open a terminal and type sudo su
2. Type gedit /etc/apt/sources.list and add the contrib and non-free sections just after main as seen in the example below:
deb http://ftp.debian.org/debian/ lenny main contrib non-free
Then save the file

3. Back at the terminal, type
apt-get update
apt-get install ipw3945-modules-$(uname -r) ipw3945d firmware-ipw3945
4. Now simply press Ctrl + Alt + backspace to restart x and login when prompted.
Your Intel PRO 3945 Wireless Network Card should now be enabled