If you are unable to connect WiFi in Ubuntu on Dell Vostro 2420. Either you install the proper driver for ubuntu or use the following command to get worked.
First of all update repository and make sure that your system is updated. Connect you laptop with network via ethernet cable and perform these tasks. Open terminal and use these commands.
1 2 3 4 | $ sudo apt-get update $ sudo apt-get upgrade |
1 2 3 | $ sudo apt-get install firmware-b43-installer |
If the above command is not works for you then try these command give below.
1 2 3 | $ sudo apt-get install firmware-b43-lpphy-installer |
I hope it will works for you, If not let me know in comment.