If you get that far, forget what I said, you're failing at the video driver stage, way after the system has booted.
Press F6 and select default, but this time try adding the term "video=vesa" without the quotes. Does that get you to a graphical log-in? If so, you can then log in as guest, and open the Pclos Control Centre (PCC) from the crossed tools icon. Select Hardware-> Set up graphical, and choose your monitor and graphics card. Do not reboot, as in a live system your settings will not survive that, but log out and back in again. Are things better. If so, that is the time to decide whether to install, as further progress would only make sense on an installed system. You might want to check other things work first.
If that doesn't work try just adding "3" without the quotes to the end of the boot line. Does that get you to a text log in? if so, log in as root and run XFDrake. This will bring up a menu to set up the monitor and graphics driver as before.
Once that is set you should be able to use "service dm restart" to get to a graphical log in.