If you've accidentally removed your Raspberry Pi OS taskbar and icons, there are a couple of ways you can get these back. The following is valid for all models of Raspberry Pi, including the Pi 400:
Terminal commands - open a new terminal window (via SSH or similar if you have no terminal icon) and enter the following command:
rm -r /home/pi/.config/lxpanel
pi@piZero2:~ $ cat /etc/os-release
PRETTY_NAME="Raspbian GNU/Linux 10 (buster)"
NAME="Raspbian GNU/Linux"
VERSION_ID="10"
VERSION="10 (buster)"
VERSION_CODENAME=buster
ID=raspbian
ID_LIKE=debian
HOME_URL="http://www.raspbian.org/"
SUPPORT_URL="http://www.raspbian.org/RaspbianForums"
BUG_REPORT_URL="http://www.raspbian.org/RaspbianBugs"
or use hostnamectl
pi@piZero2:~ $ hostnamectl
Static hostname: piZero2
Icon name: computer
Machine ID: 44b1cc9729a94a8585f892dc05aa9c4c
Boot ID: fe100077335b4532b2a109936d4eaab8
Operating System: Debian GNU/Linux 12 (bookworm)
Kernel: Linux 6.12.25+rpt-rpi-v8
Architecture: arm64
FALLBACK: running under X11
- if you must have RealVNC for some reason, you can switch the PI-OS back to using the "X11" display compositor.
- invoke "sudo raspi-config" in a terminal
- select option 6) "advanced options"
- select A6) "Wayland"
- select W1) "X11"
- a message will appear telling you that X11 is active
- use tab to select "finish".
- Reboot.