Raspberry Pi OS
STEP 1: Open terminal and execute following command:
sudo apt install network-manager network-manager-gnome modemmanager
STEP 2: Uninstall conflict packages by executing following command:
sudo apt purge openresolv dhcpcd5
STEP 3: Update DNS resolving config
If your system is Raspbian 10 or newer, please skip this step.
You can use
lsb_release -a to checkout your system version information.
If your system is Raspbian 9, use following command to update DNS resolving config:
sudo ln -sf /lib/systemd/resolv.conf /etc/resolv.conf
STEP 4: Update GUI desktop settings:
Open "Panel Settings" by right clicking the upper panel. In "Panel Applets" remove the "Wireless & Wired Network" item.
STEP 5: Reboot
The network manager applet should appear after a reboot.