My name is Krishna and I work for the Social Media and Community Team at Dell. Check the BIOS to ensure the wireless card is detected. Also verify the Wireless setting is turned on and not set to Always Off. To enter the setup, you need to tap F2 when the system boots up.
To activate wireless, Hold Down the FN Key on the keyboard and press F2. On the Inspiron 1440, the Fn key need not be used in combination with various Multimedia keys. The default setting in the BIOS is ”Multimedia Key First”. If the user wishes to use the Fn key combinations, the option in the BIOS should be accordingly set to ”Function Key First”. Hope this helps.