I have been using Ubuntu for some time. Before, my Ubuntu system could not be connected wirelessly, but only wired. It was very annoying to use it. It took half a day to completely solve this problem yesterday. It turned out that the wireless network card model of my computer was bcm43142. The network card of this model was older, so Ubuntu could not download the driver directly, so it needed to download it manually, I hope friends who encounter this problem like me can take fewer detours.
1. Enter the BIOS interface and turn off the computer's boot security. I don't know how to turn off Baidu.
2. Input the following commands at the terminal at one time:
sudo apt-get install linux-headers-generic build-essential dkms
sudo apt-get update
sudo apt-get install linux-source
sudo apt-get install --reinstall bcmwl-kernel-source
sudo modprobe wl
At this time, the computer should be able to connect wirelessly. If not, it is recommended that you first determine the model of your network card and Baidu solution according to the network card model, such as (installing bcm43142 driver under Ubuntu), which can narrow the scope of the problem.