I'm coming from windows and still new to Ubuntu. Occasionally everything freezes and I lose my taskbar and launcher. What do I do? What's the Ubuntu equivalent of ctrl+alt+del in Windows? I tried alt+f2 to bring up the "special terminal," but what can I do from there? I tried "sudo shutdown now" but that didn't fully shut down the computer and I needed a hard shutdown.
If I do manage to figure out what's wrong and fix it from the alt+f2 terminal, how do I get back to the desktop?
Alt + SysRq + r , e , i , s , u , b (busier backwards) if can not even bring up terminal.
More details, and explanation, can be found in the "Magic SysRq Key" Wikipedia article.
You may try "sudo reboot now" which will send a reboot signal and reboot the computer or sudo reboot -f now which will do the same but forcing the reboot.
Other valid commands are:
sudo shutdown -h now
or
sudo poweroff
sudo shutdown -r now
But if everything simply halted (stopped working) you may wish to first give a chance to the killall5 command in the terminal which will attempt to log out your current session without rebooting nor shutting down. This will automatically return you to the desktop session in order to choose your username and write your password.
If you already fixed the issue in the virtual terminal you can hit CtrlAltF7 in order to return to your Desktop session.
Good luck!
Please try to use the following commands after switching to tty by pressing CTRL+ALT+F2 it may help you to solve your problem:
sudo stop lightdm
sudo start lightdm
sudo restart lightdm
unity --reset
