On some machines, simply installing the xscreensaver program is not enough to have it working properly. The xscreensaver program has to be started, which is commonly done by your desktop manager.
However, some DMs do not do this (egs: IceWM).
To start the xscreensaver program manually, just type in
into a terminal.
Or, to start the xscreensaver program automatically every time you get into the X11 environment, type this into your '~/.xinitrc' file above the line specifying which DM to load.
xscreensaver -no-splash &
# # ~/.xinitrc # # Executed by startx (run your window manager from here) # xscreensaver -no-splash & # exec wmaker # exec startkde # exec icewm # exec blackbox # exec fluxbox exec xfce4-session