Open /etc/rc.conf with your favorite text editor, and locate the XSESSION=""
line. Note that the file may differ depending the distribution you're using.
Example The line should look something like this:
XSESSION="Gnome"
Replace Gnome with Fluxbox:
XSESSION="fluxbox"
Or comment the Gnome line and add a Fluxbox line:
#XSESSION="Gnome"
XSESSION="fluxbox"
Save your changes and you're set.
Edit or create a file called ~/.xsession Add this line to it (you should comment out or remove all lines that seems to be other windowmanagers):
execÂ
startfluxbox
Next time you start your computer, xdm will log you into fluxbox.