Install WIFI in Your Linux Ubuntu

You need to install wireless driver.

Insert your Ubuntu installation disk or a flash drive and copy these files from the installation disk to your Home directory:

pool/main/d/dkms/dkms_XXXXX.deb pool/restricted/b/bcmwl/bcmwl-kernel-source_XXXXX.deb

Then run the following in terminal:

sudo dpkg -i *.deb

If you are using Ubuntu 14.04.2 installation media the driver will not build

If you have 14.04.2, then download 64-BIT DRIVER FROM UBUNTU REPOSITORY or 32-BIT DRIVER, copy it to your home folder and run the same command. But you still need dkms_XXXXX.deb file from installation disk. Or you you can download it from HERE.

Ubuntu 14.04.2 has 3.16 kernel, but the installation image contains an old driver, which does not build for that kernel.

If you have UEFI BIOS, you need to disable Secure Boot to load the driver.