Ah finally, XFCE is installed in my Ubuntu. Let's call it Ubuntu Xubuntu-ed.
It does faster and more responsive in this old PC of mine.


This is how to Install XFCE in Ubuntu :

• Go to Application - System - Administration - Synaptic Package Manager
• find and check Xubuntu Desktop
• Ubuntu will download all the needed files
• after download and installation process finished, log off.
• Click Option at Login Screen to choose XFCE session. You can make it as your default Desktop Environment (DE), or just for one session. You can always revert back to Gnome, if you don't like it.