In the meantime, I installed VL 6.0 Light by means of the Live CD. The installation process ended successfully, but when I rebooted I just had a blank screen with a hyphen blinking on its left upper side. So I restarted and by means of Windows floppy disc I fixed the MBR, so I could boot Windows, at least. Then I booted again with VL cd, typing the option: linux root=/dev/hdb2 ro and, this time I didn't have any error message but obtained a command line login. I typed my user (alberto) and when I was asked the password I typed "vector", but the answer was: Login incorrect. What shall I do? Am I supposed to reinstall everything again?
I've never used LILO. Previously I used Grub with Ubuntu 9.04 + LXDE, without problems.