So, since I use a Ethernet cable for my computer, I had never to worry about the wireless, but someday I decided to use the wifi. For my surprise this magnificent wireless card wasn't working, and I was sure this couldn't be a hardware fault. After digging in the internet for a while, I have found the solution.
If during the Debian installation setup, it showed something like couldn't load the following firmware:
Code:
iwlwifi-3945-2.ucode
And your command outputs indicate this:
- cat "/var/log/messages"
 
 Code: [   14.239229] iwl3945 0000:02:00.0: firmware: requesting iwlwifi-3945-2.ucode
 [   14.304245] iwl3945 0000:02:00.0: iwlwifi-3945-2.ucode firmware file req failed: -2
 [   14.306153] iwl3945 0000:02:00.0: firmware: requesting iwlwifi-3945-1.ucode
 [   14.308434] iwl3945 0000:02:00.0: iwlwifi-3945-1.ucode firmware file req failed: -2
 [   14.310254] iwl3945 0000:02:00.0: Could not read microcode: -2
 [   14.650954] iwl3945 0000:02:00.0: firmware: requesting iwlwifi-3945-2.ucode
 [   14.653331] iwl3945 0000:02:00.0: iwlwifi-3945-2.ucode firmware file req failed: -2
 [   14.655173] iwl3945 0000:02:00.0: firmware: requesting iwlwifi-3945-1.ucode
 [   14.657535] iwl3945 0000:02:00.0: iwlwifi-3945-1.ucode firmware file req failed: -2
 [   14.659288] iwl3945 0000:02:00.0: Could not read microcode: -2
 
 
- cat "/var/log/dmesg"
 
 Code: Sep  3 14:32:02 debian wpa_supplicant[1387]: Failed to initiate AP scan.
 Sep  3 14:33:02 debian wpa_supplicant[1387]: Failed to initiate AP scan.
 Sep  3 14:34:02 debian wpa_supplicant[1387]: Failed to initiate AP scan.
 Sep  3 14:35:02 debian wpa_supplicant[1387]: Failed to initiate AP scan.
 Sep  3 14:36:02 debian wpa_supplicant[1387]: Failed to initiate AP scan.
 Sep  3 14:37:02 debian wpa_supplicant[1387]: Failed to initiate AP scan.
 Sep  3 14:38:02 debian wpa_supplicant[1387]: Failed to initiate AP scan.
 Sep  3 14:39:02 debian wpa_supplicant[1387]: Failed to initiate AP scan.
 Sep  3 14:40:02 debian wpa_supplicant[1387]: Failed to initiate AP scan.
 
 
- iwlist scan
 
 Code: wlan0     Interface doesn't support scanning : Network is down
 
 
- lspci
 
 Code: Network controller: Intel Corporation PRO/Wireless 3945ABG [Golan] Network Connection (rev 02)
 
The package you need is 
firmware-iwlwifi
You will need to do the following:
- Add the following repository to your /etc/apt/sources.list
 Code: deb http://ftp.us.debian.org/debian squeeze main contrib non-free
 
 
- Run
 Code: apt-get update
 apt-get install wireless-tools
 apt-get install firmware-iwlwifi
 
Or you can just download the .deb package from 
http://cur.lv/3lci, then installing it with:
Code:
dpkg -i <filename>.deb