Wi-Fi disappeared after an update

Wi-Fi failing after an Ubuntu kernel update is common. Work from “is the radio on?” to “does the driver load?” before you reinstall the OS.

Is the adapter there at all?

lspci -nnk | grep -A3 -i net
rfkill list
ip link

You should see a wireless interface such as wlan0 or wlp…. If rfkill says Soft blocked, unblock it:

sudo rfkill unblock wifi

Hardware blocked means a laptop kill switch or firmware setting, not Linux.

NetworkManager

nmcli general
nmcli device
sudo systemctl status NetworkManager

If the device is unmanaged, check /etc/NetworkManager/conf.d/ and netplan files in /etc/netplan/. A netplan file that sets the Wi-Fi interface to renderer: networkd will hide it from the desktop Wi-Fi menu.

Driver and kernel mismatch

uname -r
lsmod | grep -E 'iwlwifi|ath|rtw|brcm'
journalctl -b -u NetworkManager --no-pager | tail -n 50

Intel cards usually need linux-firmware. After a kernel bump, install firmware and reboot:

sudo apt install --reinstall linux-firmware
sudo reboot

If you use a USB dongle, it may need a package such as rtl8821ce-dkms. DKMS modules break when the kernel changes and the module was not rebuilt. Reinstall that package, then reboot.

You can use a phone while you fix it

USB tethering gives you a wired-style interface so you can install firmware without Wi-Fi. That is faster than guessing drivers offline.

Still stuck after firmware, rfkill, and a previous kernel from GRUB? Describe the laptop model and lspci output.