How do I revert to the previous GUI?

Question

I upgraded from 16LTS to 18. Among other problems, I am stuggling with this interface. How can I go back to the old interface?

Answer 1

By reverting to old interface, I'm pretty sure you refer to Unity, as it was default desktop environment for Ubuntu 16.04.

First, bring up your terminal window, then type following command:

sudo apt install ubuntu-unity-desktop

In middle of installation process, you will be asked to choose a display manager, as for Ubuntu 16.04 it is LightDM, meanwhile 18.04 uses GDM.

To put it up:

• If you want the login screen to look like the one from 16.04, pick LightDM.
• If you prefer current look, pick GDM.

_{Source from linuxbabe.com}

Once the installation is complete, restart your system. At the login screen, click on Ubuntu icon (in LightDM), then click Unity (default)