Ubuntu will sometimes stop detecting the wireless adapter. This can happen seemingly out of nowhere, or after a major event like a version upgrade. It is possible that there’s some hardware issue. For instance, you might’ve accidentally turned off a physical wireless switch on your device. Or, your WiFi adapter could’ve died. Most of the time though, users encounter this problem because the wireless drivers are missing. Ultimately, there are a lot of potential causes. So, we’ll explain how you can narrow down and troubleshoot the problem in your case in this article. Step 1: Resolve Hardware Issues First, you should specify network as the class and use the lshw command. This should list your wireless adapter as the output. sudo lshw -c network You can also use the lspci or lsusb commands depending on whether you’re using a PCIe wireless card or a USB adapter. lspci -v lsusb If your adapter isn’t listed by any of these commands, the kernel isn’t detecting the device at all. You can try reseating the wireless adapter and ensure that the connection isn’t loose. If that doesn’t help, the device might just be dead. You could borrow a USB WiFi adapter to quickly test this. On the other hand, if the adapter is listed, you should verify that it hasn’t been accidentally disabled. sudo rfkill list If your wireless LAN device is soft-blocked (could’ve happened because of some key combo), unblock it with the command shown below. sudo rfkill unblock all If it’s hard-blocked, check for a physical switch on your device that toggles wireless services on/off. Refer to your device manual if you don’t know where it is. Step 2: Resolve Software Issues On the software end, missing or corrupt wireless drivers are the main reason why the adapter doesn’t work. There are a couple of ways to fix this. You could try upgrading the kernel for starters. But first, ensure the WiFi driver is enabled. Open Software & Updates and switch to the Additional Drivers tab. Make sure a driver source is selected here instead of the Don’t use device option. Update Kernel Version When Ubuntu 22.04 was released, many users complained that their wireless adapter wasn’t working. This was due to some bugs with the 5.15 kernel that it shipped with. If you’re using a modern wireless card but an old kernel, the kernel may not support the hardware. Essentially, there are many reasons why updating the Ubuntu kernel to a newer stable version could resolve this problem. Since the WiFi isn’t working, you can use Ethernet or USB Tethering to download the kernel files. You could also download the files on a different machine and copy them offline. If this doesn’t help, you can try installing the wireless drivers manually. Depending on which brand of wireless card you’re using, the further steps will vary. Install Broadcom Wireless Driver In my case, I’m using a Broadcom card on my machine. For Broadcom cards, first remove the existing driver files. sudo apt purge bcmwl-kernel-source Now install the driver using apt. As mentioned earlier, you can use another connection method like Ethernet for this. Or, you can download the files on another machine, copy them, and install the driver offline. sudo apt install firmware-b43-installer bcmwl-kernel-source Install Realtek Wireless Driver For Realtek adapters, search for your adapter model on the official Realtek site. You’ll find Linux drivers as well on the Software Download page. Download the archive and extract the files. Then, go inside the extracted directory, open the terminal, and check the readme file for instructions. Usually, you’ll have an autorun script that you can run to install the driver like so sudo ./autorun.sh Install Intel Wireless Driver For Intel cards, first, download the appropriate driver for your card. Extract the files from the archive and open the terminal in this folder. Use the following command to copy the files to the firmware directory. sudo cp *.ucode /lib/firmware