How do I restart the window manager?

How to restart window manager so that styles (or whatever) are restored?

After doing /etc/init.d/networking stop they feel completely broken.

I have reinstalled lightdm. I have restarted lightdm. Nothing seems to help.

Is there a command line tool to reconfigure lightdm with?

You may need to restart your display manager to fix your problem.

11.04 and earlier.

sudo service gdm restart

Ubuntu 11.10 and newer.

sudo service lightdm restart

lightdm replaces gdm in Ubuntu 11.10

Ubuntu 15.04 and newer.

sudo service sddm restart

While restarting lightdm restarts the entire display manager, you may be able to resolve the issue by restarting unity or compiz (Unity is a compiz plugin).

Restarting Unity (nohup setsid unity OR nohup unity --restart on the CLI OR Alt+F2 and type unity) restarts the Unity shell.

If that doesn't work, restart compiz with nohup compiz --replace. You may need to restart unity again after restarting compiz.

Restarting lightdm restarts the entire display manager which is most likely to work but it will also close your running applications. Which you need to do depends on how broken your session is. If you can just restart Unity or Compiz, do that. If that doesn't work, restart lightdm.

The following wiki article has additional information about fixing LightDM issues:

https://wiki.ubuntu.com/LightDM

Press Alt+F2 and type unity, then press Enter (this is the same as running unity --replace).

If everything freezes, another place you might want to restart lightdm from is from a TTY. This will kill all your programs.

• hit Ctrl + Alt + F2
• login
• sudo service lightdm restart

A solution for KDE:

You have to type kwin --replace &

I have no idea, why @Álvaro says about sudo service kdm restart, but, at least on Kubuntu no such a service.